title: A simple green route to prepare stable silver nanoparticles with pear juice and a new selective colorimetric method for detection of cysteine.
abstract: In this work, a new cost-effective, rapid and simple method for the preparation of stable silver nanoparticles (AgNPs) was developed, which can be completed within 15 minutes at room temperature by oxidizing the reductants in pear juice with AgNO3. Compared with the most used citrate-capped AgNPs, the as-prepared AgNPs showed high stability, good biocompatibility and enhanced antibacterial activity. Based on the formation of Ag-S covalent bonds between cysteine and AgNPs as well as the electrostatic interaction of COO(-) and NH4(+) between cysteine molecules, which selectively lead to the aggregation of the as-prepared AgNPs and give a specific yellow-to-red colour change, a new selective colorimetric method for detection of cysteine was proposed with the as-prepared AgNPs by coupling the decrease of the characteristic localized surface plasmon resonance (LSPR) absorption at 406 nm of the as-prepared AgNPs and the increase of the new aggregation-induced band at 530 nm. The ratio of the absorbance at 530 nm to 406 nm (A530/A406) was found to be linearly dependent on the cysteine concentrations in the range of 5.0 × 10(-7) to 1.0 × 10(-5) M with a limit of detection of 6.8 × 10(-8) M.
authors.affiliation: Education Ministry Key Laboratory on Luminescence and Real-Time Analysis, College of Pharmaceutical Sciences, Southwest University, Chongqing 400715, PR China.
authors.forename: Jing Tao
authors.initials: JT
authors.lastname: Huang
authors.forename: Xiao Xi
authors.initials: XX
authors.lastname: Yang
authors.forename: Qiao Ling
authors.initials: QL
authors.lastname: Zeng
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D001419:Bacteria / Q000187:drug effects; D001628:Beverages; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation*; D003124:Colorimetry; D003545:Cysteine / Q000032:analysis*; D004355:Drug Stability; D055772:Green Chemistry Technology; D053768:Metal Nanoparticles / Q000737:chemistry*; D031989:Pyrus / Q000737:chemistry*; D012834:Silver / Q000737:chemistry* / Q000494:pharmacology / Q000633:toxicity
chemical_list: D000900:Anti-Bacterial Agents; D012834:Silver; D003545:Cysteine