To develop the high-performance fluorescent bio-sensors, the metal nanoparticles were employed as nanoquenchers and at- tracted reasonable attention in the design of fluorescent biosensors. In this work, silver nanopa...To develop the high-performance fluorescent bio-sensors, the metal nanoparticles were employed as nanoquenchers and at- tracted reasonable attention in the design of fluorescent biosensors. In this work, silver nanoparticles （AgNPs） were obtained via reduction of Ag＋ on FAM-labeled DNA template. For the tight binding between AgNPs and DNA, the tem- plate-synthesized AgNPs turned out high quenching efficiency and could be applied as super nanoquenchers to establish the biosensing platform for fluorescent detection. As an example, the template-synthesized DNA-AgNPs conjugates were em- ployed in sensing thiols. By forming S-Ag bonds, thiols interact intensely with AgNPs and replace the FAM-labeled DNA off from the surface of AgNPs, resulting in a fluorescence enhancement. Besides the advantages of lower background and higher signal-to-background ratio （S/B）, the conjugates present better stability, making them applicable in complicated biological fluids. To further evidence the feasibility of sensing thiols in real samples, the thiols in human urine were detected. The total amount of free thiols found in human urine was ranging from 229 μM to 302μM with the proposed sensor. To conclude the reliability, low content of Cys was added and the recovery was 98%-103%.展开更多
基金supported by the National Natural Foundation of China (21075032 & 21005026)National Key Basic Research Program (2011CB911000)Hunan Province Key Project of Scientific & Tech-nical Programs (2010TP4013-1)
文摘To develop the high-performance fluorescent bio-sensors, the metal nanoparticles were employed as nanoquenchers and at- tracted reasonable attention in the design of fluorescent biosensors. In this work, silver nanoparticles （AgNPs） were obtained via reduction of Ag＋ on FAM-labeled DNA template. For the tight binding between AgNPs and DNA, the tem- plate-synthesized AgNPs turned out high quenching efficiency and could be applied as super nanoquenchers to establish the biosensing platform for fluorescent detection. As an example, the template-synthesized DNA-AgNPs conjugates were em- ployed in sensing thiols. By forming S-Ag bonds, thiols interact intensely with AgNPs and replace the FAM-labeled DNA off from the surface of AgNPs, resulting in a fluorescence enhancement. Besides the advantages of lower background and higher signal-to-background ratio （S/B）, the conjugates present better stability, making them applicable in complicated biological fluids. To further evidence the feasibility of sensing thiols in real samples, the thiols in human urine were detected. The total amount of free thiols found in human urine was ranging from 229 μM to 302μM with the proposed sensor. To conclude the reliability, low content of Cys was added and the recovery was 98%-103%.
