A novel paper-based analytical device(PAD)was prepared and applied to determine the xanthine oxidase(XOD)inhibitory activity of Salvia miltiorrhiza extracts(SME).First,polycaprolactone was 3D printed on filter paper a...A novel paper-based analytical device(PAD)was prepared and applied to determine the xanthine oxidase(XOD)inhibitory activity of Salvia miltiorrhiza extracts(SME).First,polycaprolactone was 3D printed on filter paper and heated to form hydrophobic barriers.Then the modified paper was cut according to the specific design.Necessary reagents including XOD for the colorimetric assay were immobilized on two separate pieces of paper.By simply adding phosphate buffer,the reaction was performed on the double-layer PAD.Quantitative results were obtained by analyzing the color intensity with the specialized device system(consisting of a smartphone,a detection box and sandwich plates).The 3Dprinted detection box was small,with a size of 9.0 cm×7.0 cm×11.5 cm.Color component G performed well in terms of linearity and detection limits and thus was identified as the index.The reaction conditions were optimized using a definitive screening design.Moreover,a 10%glycerol solution was found to be a suitable stabilizer.When the stabilizer was added,the activity of XOD could be maintained for at least 15 days under 4℃ or-20℃ storage conditions.The inhibitory activity of SME was investigated and compared to that of allopurinol.The results obtained with the PAD showed agreement with those obtained with the microplate method.In conclusion,the proposed PAD method is simple,accurate and has a potential for point-of-care testing.It also holds promise for use in rapid quality testing of medicinal herbs,intermediate products,and preparations of traditional Chinese medicines.展开更多
Rapid,efficiency and portable detection systems in low-resource settings with limited laboratory equipment and technical expertise are urgently needed.Herein,an integrated platform composed of a paper-based analytical...Rapid,efficiency and portable detection systems in low-resource settings with limited laboratory equipment and technical expertise are urgently needed.Herein,an integrated platform composed of a paper-based analytical device and a smartphone detection system for Hg^2+ onsite testing was developed.Nitrogen-doped carbon dots(N-CDs)were synthesized by a simple hydrothermal method using citric acid as the carbon source and ethanediamine as the nitrogen source,which gave out bright blue fluorescence under the excitation at 350 nm UV light and the absolute fluorescence quantum yield was 17.1%.The fluorescence of the prepared N-CDs can be effectively quenched by Hg^2+.In addition,an external attachment of smartphone for illumination and external light interference was designed to trace the fluorescence signals,and a software application of Android system with simple operation program was developed to perform snapshot and image processing.The smartphone-assisted detection system was combined with the N-CDs decorated paper chip to achieve the sensitive detection of Hg^2+ in water samples.This integrated method for reliable sensing of Hg^2+ shows a good linear detection range of 10–800μmol/L(R2=0.9595)with detection limit of 1.07×10^?8 mol/L.展开更多
基金The authors would like to thank the support of the National S&T Major Project of China(Grant No.:2018ZX09201011)the National Natural Science Foundation of China(Grant No.:81503242)the Fundamental Research Funds for the Central Universities(Grant No.:2018FZA7018).
文摘A novel paper-based analytical device(PAD)was prepared and applied to determine the xanthine oxidase(XOD)inhibitory activity of Salvia miltiorrhiza extracts(SME).First,polycaprolactone was 3D printed on filter paper and heated to form hydrophobic barriers.Then the modified paper was cut according to the specific design.Necessary reagents including XOD for the colorimetric assay were immobilized on two separate pieces of paper.By simply adding phosphate buffer,the reaction was performed on the double-layer PAD.Quantitative results were obtained by analyzing the color intensity with the specialized device system(consisting of a smartphone,a detection box and sandwich plates).The 3Dprinted detection box was small,with a size of 9.0 cm×7.0 cm×11.5 cm.Color component G performed well in terms of linearity and detection limits and thus was identified as the index.The reaction conditions were optimized using a definitive screening design.Moreover,a 10%glycerol solution was found to be a suitable stabilizer.When the stabilizer was added,the activity of XOD could be maintained for at least 15 days under 4℃ or-20℃ storage conditions.The inhibitory activity of SME was investigated and compared to that of allopurinol.The results obtained with the PAD showed agreement with those obtained with the microplate method.In conclusion,the proposed PAD method is simple,accurate and has a potential for point-of-care testing.It also holds promise for use in rapid quality testing of medicinal herbs,intermediate products,and preparations of traditional Chinese medicines.
基金Supported by the National Natural Science Foundation of China(Nos.21873039,21573087,21573092)the Basic and Applied Basic Research Foundation of Guangdong Province,China(No.2019Al515010596)+1 种基金the 44Three Levels55 of Talent Project of Zhuhai College,Jilin University,China(No.2018TL006)the Science and Technology Innovation Team Project of Zhuhai College,Jilin University,China(No.2018CXKYTD005).
文摘Rapid,efficiency and portable detection systems in low-resource settings with limited laboratory equipment and technical expertise are urgently needed.Herein,an integrated platform composed of a paper-based analytical device and a smartphone detection system for Hg^2+ onsite testing was developed.Nitrogen-doped carbon dots(N-CDs)were synthesized by a simple hydrothermal method using citric acid as the carbon source and ethanediamine as the nitrogen source,which gave out bright blue fluorescence under the excitation at 350 nm UV light and the absolute fluorescence quantum yield was 17.1%.The fluorescence of the prepared N-CDs can be effectively quenched by Hg^2+.In addition,an external attachment of smartphone for illumination and external light interference was designed to trace the fluorescence signals,and a software application of Android system with simple operation program was developed to perform snapshot and image processing.The smartphone-assisted detection system was combined with the N-CDs decorated paper chip to achieve the sensitive detection of Hg^2+ in water samples.This integrated method for reliable sensing of Hg^2+ shows a good linear detection range of 10–800μmol/L(R2=0.9595)with detection limit of 1.07×10^?8 mol/L.
