A simple visual method for DNA detection during the formation of gold nanoparticles(AuNPs) was developed based on different electrostatic properties of single strand DNA(ssDNA) and double strand DNA(dsDNA).Since the s...A simple visual method for DNA detection during the formation of gold nanoparticles(AuNPs) was developed based on different electrostatic properties of single strand DNA(ssDNA) and double strand DNA(dsDNA).Since the ssDNA is easy to bind to AuNPs due to its exposed bases which could prevent saltinduced aggregation of AuNPs.The dsDNA always present negative charge because its negatively charged phosphate backbone is exposed.In this case,the dsDNA could disturb the adsorption between dsDNA and AuNPs and result in non-aggregation of AuNPs.After hybridization,chloroauric acid and ascorbic acid were added to the mixture solution,and the solution changed to red immediately and turned to purple in10 min in the present of target DNA.TEM results confirmed that the change of color stemed from aggregation of AuNPs.In order to obtain accurate results by naked eye,the DNA detection assay should be conducted under pH 7.0.展开更多
基金financially supported by the National Key Research and Development Program of China (No.2017YFA0205301)the National Natural Science Foundation of China (Nos.61527806, 81902153 and 61871180)+2 种基金the Natural Science Foundation of Hunan Province (No.2017JJ2069)the Hunan Key Research Project (No.2017SK2174)the Programs for Changjiang Scholars and Innovative Research Team in University (No.IRT_15R13)
文摘A simple visual method for DNA detection during the formation of gold nanoparticles(AuNPs) was developed based on different electrostatic properties of single strand DNA(ssDNA) and double strand DNA(dsDNA).Since the ssDNA is easy to bind to AuNPs due to its exposed bases which could prevent saltinduced aggregation of AuNPs.The dsDNA always present negative charge because its negatively charged phosphate backbone is exposed.In this case,the dsDNA could disturb the adsorption between dsDNA and AuNPs and result in non-aggregation of AuNPs.After hybridization,chloroauric acid and ascorbic acid were added to the mixture solution,and the solution changed to red immediately and turned to purple in10 min in the present of target DNA.TEM results confirmed that the change of color stemed from aggregation of AuNPs.In order to obtain accurate results by naked eye,the DNA detection assay should be conducted under pH 7.0.
