title: Ultrasensitive detection of target analyte-induced aggregation of gold nanoparticles using laser-induced nanoparticle Rayleigh scattering.
abstract: Detection of salt- and analyte-induced aggregation of gold nanoparticles (AuNPs) mostly relies on costly and bulky analytical instruments. To response this drawback, a portable, miniaturized, sensitive, and cost-effective detection technique is urgently required for rapid field detection and monitoring of target analyte via the use of AuNP-based sensor. This study combined a miniaturized spectrometer with a 532-nm laser to develop a laser-induced Rayleigh scattering technique, allowing the sensitive and selective detection of Rayleigh scattering from the aggregated AuNPs. Three AuNP-based sensing systems, including salt-, thiol- and metal ion-induced aggregation of the AuNPs, were performed to examine the sensitivity of laser-induced Rayleigh scattering technique. Salt-, thiol-, and metal ion-promoted NP aggregation were exemplified by the use of aptamer-adsorbed, fluorosurfactant-stabilized, and gallic acid-capped AuNPs for probing K(+), S-adenosylhomocysteine hydrolase-induced hydrolysis of S-adenosylhomocysteine, and Pb(2+), in sequence. Compared to the reported methods for monitoring the aggregated AuNPs, the proposed system provided distinct advantages of sensitivity. Laser-induced Rayleigh scattering technique was improved to be convenient, cheap, and portable by replacing a diode laser and a miniaturized spectrometer with a laser pointer and a smart-phone. Using this smart-phone-based detection platform, we can determine whether or not the Pb(2+) concentration exceed the maximum allowable level of Pb(2+) in drinking water.
authors.affiliation: Department of Chemistry, National Sun Yat-sen University, 70, Lien-hai Road, Kaohsiung 804, Taiwan.
authors.forename: Jia-Hui
authors.initials: JH
authors.lastname: Lin
authors.affiliation: Department of Chemistry, National Sun Yat-sen University, 70, Lien-hai Road, Kaohsiung 804, Taiwan; School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Taiwan; National Sun Yat-sen University and Center for Nanoscience & Nanotechnology, Taiwan. Electronic address: tsengwl@mail.nsysu.edu.tw.
authors.forename: Wei-Lung
authors.initials: WL
authors.lastname: Tseng
mesh_terms: D043383:Adenosylhomocysteinase / Q000737:chemistry; D002413:Cations, Divalent; D040421:Cell Phone; D060766:Drinking Water / Q000737:chemistry*; D005707:Gallic Acid / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D006801:Humans; D007834:Lasers; D007854:Lead / Q000032:analysis*; D008027:Light; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D009391:Nephelometry and Turbidimetry / Q000295:instrumentation / Q000379:methods*; D012435:S-Adenosylhomocysteine / Q000737:chemistry; D012542:Scattering, Radiation; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D002413:Cations, Divalent; D060766:Drinking Water; D014874:Water Pollutants, Chemical; D007854:Lead; D005707:Gallic Acid; D006046:Gold; D012435:S-Adenosylhomocysteine; D043383:Adenosylhomocysteinase
keywords: Gold nanoparticles; Laser-induced Rayleigh scattering; Sensor; Smart phone