Deep eutectic solvent-based manganese dioxide nanosheets composites for determination of DNA by a colorimetric method
BMC Chemistry volume 17, Article number: 15 (2023)
Nucleic acid is the carrier of genetic information and the keymolecule in life science. It is important to establish a simple and feasible method for nucleic acid quantification in complex biological samples.
Four kinds of hydrogen bond acceptors (choline chloride (ChCl), L-carnitine, tetrabutylammonium chloride (TBAC) and cetyltrimethylammonium bromide (CTAB)) were used to synthesize deep eutectic solvents (DESs) with hexafluoroisopropanol (HFIP). DESs based manganese dioxide (MnO2) nanosheets composites was synthesized and characterized. DNA concentration was determined by a UVVis spectrometer. The mechanism of DNA-DES/MnO2 colorimetric system was further discussed.
The composite composed of DES/MnO2 exhibited excellent oxidase-like activity and could oxidize 3,3’,5,5’ -tetramethylbenzidine (TMB) to produce a clear blue change with an absorbance maximum at 652 nm. When DNA is introduced, the DNA can interact with the DES by hydrogen bonding and electrostatic interactions, thereby inhibiting the color reaction of DES/MnO2 with TMB. After condition optimization, ChCl/HFIP DES in 1:3 molar ratio was used for the colorimetric method of DNA determination. The linear range of DNA was 10–130 µg/mL and exhibited good selectivity.
A colorimetric method based on DES/MnO2 was developed to quantify the DNA concentration. The proposed method can be successfully used to quantify DNA in bovine serum samples.
Deep eutectic solvents (DESs), an emerging class of environmentally friendly solvents are formed by hydrogen bond acceptors (HBAs) and hydrogen bond donors (HBDs) in an appropriate ratio. The formation of strong hydrogen bonds leads to a melting point lower than that of each individual component . DESs possess numerous excellent properties including low volatility, ease of storage, stable physical and chemical properties, and good biocompatibility [2, 3]. In addition, the physical or chemical properties of DESs can be tuned by selecting HBAs and HBDs species [4, 5]. Owing to their excellent biocompatibility, DESs have been widely applied in the partitioning of biomass, such as proteins and, nucleotides, and for improving the efficiency of enzymatic reactions [6,7,8,9,10,11].
Nucleic acid, the carrier of genetic information, is a crucial molecule in life sciences. High-purity nucleic acids are the foundation of studies in clinical trials, genomics, food safety and other fields [12, 13]. However, real samples of nucleic acid usually contain impurities such as metal ions and proteins, which interfere with the reliability of the experimental analysis. Consequently, establishing a convenient and simple method for the accurate quantification of nucleic acids in complex biological samples is of great significance. DESs have been used as green substitutes for traditional organic solvents for nucleic acid extraction from aqueous solutions [8, 9, 11, 14]. In addition, Mondal et al. reported the solubility of DNA in DESs and confirmed the chemical and structural stability of DNA after six months of storage in DESs comprising glycerol and ethylene glycol . Sharma et al. reported that hydrogen bonding is the major driving force that promotes the dissolution of DNA in DESs . A recent and promising improvement in DES-based DNA purification approaches is the use of a combination of nanomaterials [2, 17,18,19].
Manganese dioxide (MnO2) is a functional transition metal oxide and its nanosheets have unique properties, such as a high specific surface area and oxidase-mimicking activity [20, 21]. It has been applied in sensing technology [22, 23], cell imaging , magnetic resonance imaging , and biomedical analysis [26,27,28]. 3,3’,5,5’-Tetramethylbenzidine (TMB) is a commonly used chromogenic substrate that can change from colorless to blue in the presence of MnO2 nanosheets with oxidase-like activity . A colorimetric method based on MnO2 nanosheets/TMB has been reported for the detection and quantification of target compounds and biomacromolecules, including glucose, pesticides, metal ions, antibacterial agents, and nucleic acid [14, 20,21,22, 29, 30].
Hexafluoroisopropanol (HFIP) is a perfluorinated alcohol with a high density and strong hydrophobicity . HFIP has proven to be an excellent HBD for preparation of high-density HFIP-based DESs with various HBAs [4, 32]. At present, HFIP-based DESs have been successfully employed in the purification of pesticides, anthraquinones, and dyes [4, 31, 33], but they are also used as environmental reaction media . In this study, HFIP-based DESs combined MnO2 nanosheets were synthesized and employed for the quantification of DNA for the first time. Choline chloride (ChCl) was selected as the HBA to synthesize the DES with HFIP. The DNA quantification procedure was based on the colorimetric reaction between DES/MnO2 and TMB. We demonstrated that this method could accurately quantify DNA from bovine serum samples.
Materials and Methods
Cetyltrimethylammonium bromide (CTAB), sodium acetate (NaAc), anhydrous acetic acid, KMnO4, NaOH, (NH4)2SO4, K2HPO4, KH2PO4, Na2CO3, Na2HPO4 and Na2SO4 were purchased from Sinopharm Chemical Reagent Co., Ltd. (Shanghai, China). Salmon sperm DNA sodium salt, morpholine ethanesulfonic acid (MES), HFIP, ChCl, L-carnitine, tetrabutylammonium chloride (TBAC), and TMB were purchased from Macklin (Shanghai, China). Bovine serum was purchased from Haoyang Biological Manufacture Co., Ltd. (Tianjin, China). All other reagents were of analytical grade and were commercially available. Deionized (DI) water (18.25 MΩ) was used in all the experiments.
The surface modification of the obtained DES and DES/MnO2 was investigated using a Nicolet 470 fourier transform infraed (FT-IR) spectrometer (Thermo Fisher Scientific, USA) in a KBr pellet at room temperature. Nuclear magnetic resonance (1 H NMR) spectra were obtained using an Avance III 400 MHz spectrometer (Bruker, Germany) and the morphology of the MnO2 nanosheets was observed using a JEM-2100 transmission electron microscope (TEM) (JEOL, Japan). Thermal gravimetric analysis (TGA) was performed using TG 209F1 (NETZSCH, Germany). A PHI5000 VersaProbe (PHI, Japan) was used for X-ray photoelectron spectroscopy (XPS) analysis. The zeta potential and dynamic light scattering (DLS) were analyzed using a Zeta sizer Nano ZS90 (Malvern, England). Agitation and extraction were performed using an UXI orbital shaker (Huxi, China). The concentration of the DNA solution was determined using a UV-1600PC ultraviolet-visible (UV-Vis) spectrophotometer (XIPU, China). The obtained MnO2 nanosheets were dried using an XMTD-8222 vacuum dryer (Jinghong, China). The obtained DES-MnO2 was dried in a ZX-LGJ-1 A freeze dryer (Zhixin, China).
Preparation of DES
Four types of DESs (ChCl/HFIP, L-carnitine/HFIP, TBAC/HFIP, and CTAB/HFIP) were synthesized by stirring a designed amount of HBAs and HFIP in a 150 mL thick-walled pressure-resistant flask at an appropriated temperature until a homogeneous transparent liquid was formed. After optimization, a DES composed of ChCl/HFIP at a 1:3 molar ratio was prepared.
Preparation of MnO2 nanosheets
MnO2 nanosheets were synthesized according to a previous reported method [35, 36]. 20 mg KMnO4 was accurately weighed and transferred to a 50 mL conical flask, dissolved in 18 mL of DI water, and stirred for 1 h at room temperature. Subsequently, 60 mg of CTAB was added to the flask and stirred continuously until a stable emulsion was formed. Next, 2 mL of 0.1 mol/L MES was poured into the mixture and reacted for 6 h. Finally, the MnO2 nanosheets were washed three times with DI water. After centrifuging at 12,000 rpm for 5 min, the MnO2 nanosheets were dried at 60 °C under vacuum.
Preparation of DES/MnO2
DES/MnO2 was prepared using a previously reported method  with some modifications. Briefly, 20 mg of MnO2 nanosheets were dispersed in 2 mL of methanol and 0.5 mL of synthesized ChCl/HFIP DES and the mixture was ultrasonicated for 2 h at room temperature. The resulting solution was centrifugated at 5000 rpm for 10 min and washed three times with methanol. Finally, the DES/MnO2 solid was collected by vacuum freeze-drying.
Colorimetric reaction of DES/MnO2 and TMB
50 µL of TMB (2 mg/mL) was dissolved in 1800 µL NaAc (pH 4.0). Subsequently, 150 µL DES/MnO2 of different concentrations were added to this above mixed solution and shaken on an incubator shaker for 30 min at room temperature. Finally, the resulting solution was measured at 652 nm by UV-Vis spectrometer.
Colorimetric determination of DNA concentration
Next, 150 µL of DES/MnO2 (0.1 mg/mL) was added to 1750 µL NaAc (pH 4.0) aqueous solution. Therefore, 50 µL of DNA solutions with different concentrations was added to the mixed solution. After the addition of 50 µL TMB (2 mg/mL), the mixture was shaken for 30 min at room temperature. Finally, the absorbance of the resulting solution was measured at 652 nm using a UV-Vis spectrometer.
An aqueous solution of 150 µL DES/MnO2 (0.1 mg/mL), 50 µL TMB (2 mg/mL), and 1850 µL NaAc (pH 4.0) was prepared to conduct selectivity experiments. Various non-specific proteins, carbohydrates, and salts were selected to replace DNA and were added to the prepared aqueous solution for the DNA selectivity test. The mixture was then shaken for 30 min at room temperature. Finally, the absorbance of the resulting solution was measured at 652 nm using a UV-Vis spectrometer.
Results and discussion
ChCl, L-carnitine, TBAC, and CTAB were selected as HBA, and HFIP was selected as the HBD. To determine the extraction potential of the proposed DESs for DNA extraction, six inorganic salts ((NH4)2SO4, K2HPO4, KH2PO4, Na2CO3, Na2HPO4, and Na2SO4) were used as phase separation inducers. A system of 0.5 mL DES (ChCl/HFIP, L-carnitine/HFIP, TBAC/HFIP, and CTAB/HFIP) and 0.8 g inorganic salts ((NH4)2SO4, K2HPO4, KH2PO4, Na2CO3, Na2HPO4, and Na2SO4) were prepared in 5 mL of aqueous solution. The molar ratio of HBAs to the HFIP was 1:2. DNA (10 µg/mL) was added to investigate the extraction performance of the two-phase system. After separating into two phases, the bottom phase was removed and detected at 260 nm using a UV detector. The extraction results are summarized in Table S1. It can be seen that the DES comprising ChCl and HFIP was suitable for DNA extraction.
Figure S1 shows the effect of the ChCl:HFIP molar ratio on DNA extraction. A system involving 0.5 mL DES with different molar ratios (1:1.5, 1:2, 1:3, and 1:4) and 0.8 g Na2SO4 was prepared in 5 mL of aqueous solution. It was clear that DNA extraction increased with the molar ratio varying from 1:1.5 to 1:3 and thereafter a declined at molar ratio of 1:4. In conclusion, a DES comprising ChCl and HFIP in a 1:3 molar ratio was suitable for DNA extraction.
Characterization of DES and DES/MnO2
FT-IR spectra and 1 H NMR were used to characterize the synthesized DESs. As shown in Fig. S2 the stretching vibration peaks of O-H in pure HFIP and ChCl were observed at 3424 cm− 1 and 3293 cm− 1, respectively, which shifted to a lower wavenumber of 3165 cm− 1 in ChCl/HFIP. The shift of the –OH stretching vibration indicated the existence of hydrogen bonding between ChCl and HFIP. In addition, no new peaks were detected, demonstrating that no chemical reaction occurred during DES synthesis. As shown in Fig. S3, the 1 H NMR of ChCl/HFIP is as follows: δ 4.60 (s, 1 H), 4.01 (dd, 2 H), 3.52 (m, 2 H), 3.21 (d, 9 H). These results verified that the HFIP/ChCl DES was successfully synthesized.
The high-resolution TEM image of the prepared MnO2 nanosheets (Fig. 1a) revealed the presence of large two-dimensional sheet-like structures, which provided a large surface area for the reaction with TMB, a chromogenic substrate. Figure 1b shows the FT-IR characterization spectrum of the MnO2 nanosheets, DES, and DES/MnO2, where the MnO2 nanosheets exhibited a distinct band at 554 cm− 1, which was attributed to Mn-O and Mn-O-Mn. The DES/MnO2 spectrum revealed the presence of some characteristic peaks of DES, such as the absorption peaks at 2850 cm− 1 and 2920 cm− 1, attributed to C-H, and the absorption peaks at 1173 cm− 1 and 1190 cm− 1 attributed to C-O. These results indicate the successful modification of the MnO2 nanosheets by DES. TGA of the MnO2 nanosheets and DES/MnO2 (Fig. 1c) was performed to determine the mass percentages of the DES in the composites. The decomposition of the DES occurred at 225 °C with a mass loss of approximately 14%, indicating that the DES successfully modified the surface of the nanosheets at a grafting rate of approximately 14%. Figure 1d shows the high-resolution XPS profile of the DES/MnO2. The N 1s spectrum (Fig. 1e) confirmed the presence of DES. Moreover, as shown in Fig. 1f, the two characteristic peaks with binding energies of 654.16 eV and 642.68 eV were attributed to the Mn 2p1/2 and Mn 2p3/2 of MnO2, respectively. The XPS spectra also indicated the successful synthesis of DES/MnO2.
DLS and zeta potential measurements were used to investigate the mechanism underlying the detection of DNA by DES/MnO2. The zeta potential of the pure DNA, MnO2 nanosheets, DES/MnO2 and DNA-DES/MnO2 were recorded. As shown in Fig. 2a, the zeta potential of the MnO2 nanosheet was − 23.77 mV. After combining with DES, the zeta potential of DES/MnO2 was approximately − 19.57 mV, which is slightly higher than that of the pure MnO2 nanosheets. It was proven that the HFIP/ChCl DES was positively charged. Thus, the negatively charged DNA can bind to the DES through electrostatic interactions and thereafter adsorb onto the surface of DES/MnO2. In addition, HFIP contains a large number of hydroxyl groups and is selected as the HBD in the synthesis of DES, which can enhance the hydrogen bond interaction between DES/MnO2 and DNA. Therefore, the surface zeta potential of DNA-DES/MnO2 was − 22.9 mV, which is slightly lower than that of DES/MnO2. Figure 2b shows the DLS results. The particle size of the DES/MnO2 was approximately 342 nm. After combining with DNA, the size of the new aggregates was 459 nm, indicating that DNA-DES/MnO2 was formed.
Measurement of the DES/MnO2 oxidase activity
TMB was selected as the substrate to investigate the oxidase activity because DES/MnO2 possess an oxidase-like activity and can directly oxidize TMB into oxidized TMB (oxTMB). Figure 3a shows neither a significant absorption peak (red) for DES/MnO2 nor a significant absorption peak for TMB from 400 to 800 nm (blue). However, owing to the oxidase-like activity of the MnO2 nanosheets, a deep blue color (characteristic absorption peak at 652 nm) was observed upon the binding of DES/MnO2 with TMB owing to the oxidation of the colorless TMB.
To verify the catalytic activity of DES/MnO2 further, different concentrations of DES/MnO2 (0–30 µg/mL) were reacted with TMB. The absorbance gradually increased with increasing DES/MnO2 concentration (Fig. 3b). However, the absorption intensity decreased when the concentration of DES/MnO2 was higher than 22 µg/mL, because TMB or oxTMB may have been denatured. Figure 3b shows a series of color changes. Furthermore, the absorbance signal increased linearly with an increase in the DES/MnO2 concentration in the range of 0–18 µg/mL, and the linear regression had an equation of y = 0.128x + 0.115 (R2 = 0.996).
The colorimetric reaction of the DES/MnO2 composites with TMB under different pH conditions was thereafter evaluated (Fig. 4), and the strongest absorbance response was detected at pH 4.0, which was selected as the optimal pH.
Colorimetric determination of DNA concentration
To explore the utility of the DES/MnO2-TMB system, a colorimetric quantitative analysis of DNA was performed under optimal conditions, and a standard curve was plotted. The difference in absorbance increased with an increase in DNA concentration until it eventually reached a plateau (the image depicts the gradual lightening of the solution color) (Fig. 5). Furthermore, the absorbance difference (ΔA), where ΔA denotes the difference in absorbance of the DES/MnO2-TMB system before (A0) and after (A) the addition of DNA, exhibited a good linear relationship with DNA concentration in the range of 10–130 µg/mL, and the linear equation was y = 2.019x + 0.004 (R2 = 0.996). The adsorption of DNA onto the surface of DES/MnO2 was mainly attributed to electrostatic interactions and hydrogen bonding between the phosphate group of DNA and the cationic part of the DES. With the addition of DNA adsorbed on the surface of DES/MnO2, the colorimetric reaction of DES/MnO2 with TMB was inhibited .
To investigate the specificity of this method for DNA detection, the absorption spectral response of the DES/MnO2-TMB system to various interfering substrates (non-specific proteins, carbohydrates, and salts) was studied (Fig. 6). The first column shows the absorption intensities of the DES/MnO2-TMB system without the addition of DNA or other interfering substances. RNA had a greater effect on the absorption intensity, whereas proteins such as bovine serum albumin (BSA), hemoglobin, and cytochrome C had a weaker effect. This is primarily because RNA has a structure similar to that of DNA, resulting in a similar inhibitory effect. Consequently, when testing samples containing both DNA and RNA, masking or pre-treatment steps are required.
Application to real samples
To evaluate the viability of our designed assay for practical applications, DES/MnO2 was used to detect DNA in bovine serum. Different concentrations of DNA standard solution were spiked into the bovine serum samples to examine the recovery. The analytical results are summarized in Table 1. The recoveries were within the range of 102.73-107.08% for the three known concentrations of added DNA, and the relative standard deviation (RSD) was less than 3.63%. These results demonstrate the potential application of the proposed colorimetric method for the detection of DNA in real samples.
Herein, we report the synthesis of a DES/MnO2 composite that efficiently catalyzes TMB. The composition and molar ratio of DESs were evaluated and DES composed of ChCl and HFIP with molar ratio of 1:3 was suitable for DNA extraction. The addition of DNA to the system significantly inhibited the colorimetric reaction and reduced the absorbance of DES/MnO2-TMB owing to hydrogen bonding and electrostatic interactions between DNA and the DES. Consequently, a colorimetric method based on DES/MnO2 was developed to quantify the DNA concentration. This method exhibited good linearity and specificity and could be used to determine DNA concentration in a simple and rapid manner. Consequently, it exhibits potential for application in DNA detection.
The datasets used and/or analyzed during the current study are available from the corresponding author on reasonable request.
Deep eutectic solvents
- MnO2 :
Hydrogen bond acceptors
Hydrogen bond donors
Morpholine ethanesulfonic acid
Nuclear magnetic resonance
Transmission electron microscope
Dynamic light scattering
Thermal gravimetric analysis
X-ray photoelectron spectroscopy
Bovine serum albumin.
Ramezani AM, Ahmadi R, Yamini Y. Homogeneous liquid-liquid microextraction based on deep eutectic solvents. Trac-Trend Anal Chem. 2022;149:116566.
Peng F, Liu M, Wang X, Ding X. Synthesis of low-viscosity hydrophobic magnetic deep eutectic solvent: selective extraction of DNA. Anal Chim Acta. 2021;1181:338899.
Shakirova F, Shishov A, Bulatov A. Hydrolysis of triglycerides in milk to provide fatty acids as precursors in the formation of deep eutectic solvent for extraction of polycyclic aromatic hydrocarbons. Talanta. 2022;237:122968.
Xu K, Xu P, Wang Y. Aqueous biphasic systems formed by hydrophilic and hydrophobic deep eutectic solvents for the partitioning of dyes. Talanta. 2020;213:120839.
Hang NT, Uyen TTT, Phuong NV. Green extraction of apigenin and luteolin from celery seed using deep eutectic solvent. J Pharmaceut Biomed. 2021;207:114406.
Xu W, Wang Y, Wei X, Chen J, Xu P, Ni R, Meng J, Zhou Y. Fabrication of magnetic polymers based on deep eutectic solvent for separation of bovine hemoglobin via molecular imprinting technology. Anal Chim Acta. 2019;1048:1–11.
Xu K, Wang Y, Huang Y, Li N, Wen Q. A green deep eutectic solvent-based aqueous two-phase system for protein extracting. Anal Chim Acta. 2015;864:9–20.
Li N, Wang Y, Xu K, Wen Q, Ding X, Zhang H, Yang Q. High-performance of deep eutectic solvent based aqueous bi-phasic systems for the extraction of DNA. RSC Adv. 2016;6:84406.
Zhang H, Wang Y, Zhou Y, Xu K, Li N, Wen Q, Yang Q. Aqueous biphasic systems containing PEG-based deep eutectic solvents for high-performance partitioning of RNA. Talanta. 2017;170:266–74.
Nian B, Li X. Can deep eutectic solvents be the best alternatives to ionic liquids and organic solvents: a perspective in enzyme catalytic reactions. Int J Biol Macromol. 2022;217:255–69.
Xu P, Wang Y, Chen J, Wei X, Xu W, Ni R, Meng J, Zhou Y. A novel aqueous biphasic system formed by deep eutectic solvent and ionicliquid for DNA partitioning. Talanta. 2018;189:467–79.
Chen Y, Liu Y, Shi Y, Ping J, Wu J, Chen H. Magnetic particles for integrated nucleic acid purification, amplification and detection without pipetting. Trac-Trend Anal Chem. 2020;127:115912.
Emaus MN, Varona M, Eitzmann DR, Hsieh S, Zeger VR, Anderson JI. Nucleic acid extraction: Fundamentals of sample preparationmethodologies, current advancements, and future endeavors. Trac-Trend Anal Chem. 2020;130:115985.
Chen J, Wang Y, Wei X, Ni R, Meng J, Xu F, Liu Z. A composite prepared from MnO2 nanosheets and a deep eutectic solvent as an oxidase mimic for the colorimetric determination of DNA. Microchim Acta. 2020;187:7.
Mondal D, Sharma M, Mukesh C, Gupta V, Prasad K. Improved solubility of DNA in recyclable and reusable bio-based deep eutectic solvents with long-term structural and chemical stability. Chem Commun. 2013;49:9606–8.
Sharma G, Sequeira RA, Pereira MM, Maity TK, Chudasama NA, Prasad K. Are ionic liquids and deep eutectic solvents the same?: fundamental investigation from DNA dissolution point of view. J Mol Liq. 2021;328:115386.
Xu K, Wang Y, Zhang H, Yang Q, Wei X, Xu P, Zhou Y. Solid-phase extraction of DNA by using a composite preparedfrom multiwalled carbon nanotubes, chitosan, Fe3O4 and a poly(ethylene glycol)-based deep eutectic solvent. Microchim Acta. 2017;184:4133–40.
Meng J, Wang Y, Zhou Y, Chen J, Wei X, Ni R, Liu Z, Xu F. A composite consisting of a deep eutectic solvent and dispersedmagnetic metal-organic framework (type UiO-66-NH2) for solid-phase extraction of RNA. Microchim Acta. 2020;187:58.
Wang X, Liu M, Peng F, Ding X. Hydrophobic magnetic deep eutectic solvent: synthesis, properties, and application in DNA separation. J Chromatogr A. 2021;1659:462626.
Ge J, Xing K, Geng X, Hu Y, Shen X, Zhang L, Li Z. Human serum albumin templated MnO2 nanosheets are oxidase mimics for colorimetric determination of hydrogen peroxide and for enzymatic determination of glucose. Microchim Acta. 2018;185:559.
Sheng E, Lu Y, Tan Y, Xiao Y, Li Z, Dai Z. Oxidase-mimicking activity of ultrath in MnO2 nanosheets in a colorimetric assay of chlorothalonil in food samples. Food Chem. 2020;331:127090.
He L, Lu Y, Wang F, Jing W, Chen Y, Liu Y. Colorimetric sensing of silver ions based on glutathione-mediated MnO2 nanosheets. Sens Actuator B. 2018;254:468–74.
Mu X, Liu X, Ye X, Zhang W, Li L, Ma P, Song D. Branched poly(ethylenimine) carbon dots-MnO2 nanosheets based fluorescent sensory system for sensing of malachite green in fish samples. Food Chem. 2022;394:133517.
Zhang Y, Ma C, Ma C, Xiang Y, Mu S, Zheng Z, Liu X, Zhang H. Ratiometric fluorescent detection and imaging of microRNA in living cells with manganese dioxide nanosheet-active DNAzyme. Talanta. 2021;233:122518.
Lyu M, Zhu D, Kong X, Yang Y, Ding S, Zhou Y, Quan H, Duo Y, Bao Z. Glutathione-depleting nanoenzyme and glucose oxidase combination for hypoxia modulation and radiotherapy enhancement. Adv Healthc Mater. 2020;9:1901819.
Zhang T, Gan Z, Zhen S, Hu Y, Hu X. Monitoring of glutathione using ratiometric fluorescent sensor based on MnO2 nanosheets simultaneously tuning the fluorescence of rhodamine 6G and thiamine hydrochloride. Spectrochim Acta A. 2022;271:120942.
Fan Z, Zhou Z, Zhang W, Zhang X, Lin J. Inkjet printing based ultra-small MnO2 nanosheets synthesis for glutathione sensing. Talanta. 2021;225:121989.
Wang S, Zheng H, Zhou L, Cheng F, Liu Z, Zhang H, Wang L, Zhang Q. Nanoenzyme-reinforced injectable hydrogel for healing diabetic wounds infected with multidrug resistant bacteria. Nano Lett. 2020;20:5149–58.
Song H, Wang Y, Wang G, Wei H, Luo S. Ultrathin two-dimensional MnO2 nanosheet as a stable coreactant of 3,3′,5,5′-tetramethylbenzidine chromogenic substrate for visual and colorimetric detection of iron (II) ion. Microchim Acta. 2017;184:3399–404.
Ma K, Liang L, Zhou X, Tan W, Hu O, Chen Z. A redox-induced dual-mode colorimetric and fluorometric method based on N-CDs and MnO2 for determination of isoniazid in tablets and plasma samples. Spectrochim Acta A. 2021;247:119097.
Tian Y, Li Y, Mei J, Deng B, Xiao Y. Hexafluoroisopropanol-modified cetyltrimethylammonium bromide/sodium dodecyl sulfate vesicles as a pseudostationary phase in electrokinetic chromatography. J Chromatogr A. 2015;1404:131–40.
Deng W, Zong Y, Xiao Y. Hexafluoroisopropanol-based deep eutectic solvent/salt aqueous two-phase systems for extraction of anthraquinones from rhei radix et rhizoma samples. ACS Sustain Chem Eng. 2017;5:4267–75.
Deng W, Yu L, Li X, Chen J, Wang X, Deng Z, Xiao Y. Hexafluoroisopropanol-based hydrophobic deep eutectic solvents fordispersive liquid-liquid microextraction of pyrethroids in tea beverages andfruit juices. Food Chem. 2019;274:891–9.
Wang L, Dai D, Chen Q, He M. Rapid and green synthesis of phenols catalyzed by a deep eutectic mixture based on fluorinated alcohol in water. J Fluor Chem. 2014;158:44–7.
Zuo Q, Chen Y, Chen Z, Yu R. A novel ratiometric fluorescent sensing method based on MnO2 nanosheet for sensitive detection of alkaline phosphatase in serum. Talanta. 2020;209:120528.
Wang H, Li Y, Bai H, Liu Y. DNA-templated au nanoclusters and MnO2 sheets: a label-free and universal fluorescence biosensing platform. Sens Actuator B. 2018;259:204–10.
This work was supported by the National Natural Science Foundation of China (81802109).
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Table S1 The extraction efficiency of DESs with inorganic salts for the DNA extraction. Fig. S1 The effect of ChCl:HFIP molar ratio on DNA extraction. Fig. S2 FT-IR spectra of ChCl/HFIP DES. Fig. S3 1H NMR spectra of ChCl/HFIP DES. Table S2 The data for Fig. 6.
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Xu, J., Yang, Y., Du, J. et al. Deep eutectic solvent-based manganese dioxide nanosheets composites for determination of DNA by a colorimetric method. BMC Chemistry 17, 15 (2023). https://doi.org/10.1186/s13065-023-00922-5