Organophosphorous pesticide(OP) contamination has serious adverse effects on human health and the environment. Due to the toxicity of OPs and the threat presented by their accidental or intentional release in populate...Organophosphorous pesticide(OP) contamination has serious adverse effects on human health and the environment. Due to the toxicity of OPs and the threat presented by their accidental or intentional release in populated areas, the determination and monitoring of these OPs in food products and environment is of great importance. OPs are present in very small quantities and therefore, methods for their detection need to be highly sensitive and selective. Here, we aimed to develop a simple and selective aptamer-based colorimetric assay for the detection of omethoate, which is one of the commonly used OPs. The principle of the assay is that single-stranded DNA(ss DNA)-wrapped gold nanoparticles(Au NPs) are resistant to salt-induced aggregation. By employing an "artificial antibody" organophosphorous pesticide-binding aptamer(OBA) as the recognition element, aptamer-wrapped Au NPs(Au-apta) show high selectivity towards omethoate, resulting in the disconnection of aptamers from Au NPs and the aggregation of Au NPs. As there is a significant color change from the interparticle plasmon coupling during the aggregation of Au NPs, the established assay showed good linearity between 0.1 and 10 μmol/L, with a low detection limit of 0.1 μmol/L. Other OPs such as profenofos, phorate, and isocarbophos would not interfere with the detection of omethoate despite having similar structures. Thus, the colorimetric method shows potential for use in the detection of omethoate in real soil samples.展开更多
This review begins with an overview of the appealing properties and various applications of gold nanoparticles, and briefly summarizes recent advances in using unmodified gold nanoparticles to detect different kinds o...This review begins with an overview of the appealing properties and various applications of gold nanoparticles, and briefly summarizes recent advances in using unmodified gold nanoparticles to detect different kinds of targets including nucleic acids, proteins, metal ions and small organic molecules. The key point to the unmodified gold nanoparticle-based visual detection assay is to control dispersion and aggregation of colloidal nanoparticles by targets of interest, which usually relies on affinities between gold nanoparticles and targets. The degree of dispersion or aggregation can be visualized through the change of the solution color or the precipitation of nanoparticles from the solution. Thus, the existence of the target molecules can be trans-lated into optical signals and monitored by the naked eye conveniently. Finally, some future prospects of this research field are given.展开更多
Herein, a novel probe based on poly(N,N′-methylenebisacylamide) protected Au NPs(PDMAM-Au NPs) was developed for determination of silver ions. The thiol-terminated PDMAM was synthesized by the reversible addition fra...Herein, a novel probe based on poly(N,N′-methylenebisacylamide) protected Au NPs(PDMAM-Au NPs) was developed for determination of silver ions. The thiol-terminated PDMAM was synthesized by the reversible addition fragmentation chain transfer radical polymerization. Then, the PDMAM-Au NPs were prepared by a simple, one-pot and green process. It has been observed that existence of the silver ions evoked a small red-shift to the emission peak of PDMAM-Au NPs and an obvious increase in UV absorption. The detection limit of the present method for silver ions was 0.5 ?mol/L, with a linear range of 1.0–1000 ?mol/L. Moreover, the possible mechanism for enhanced UV absorption intensity with enlarged diameter of PDMAM-Au NPs was explored and discussed briefly. The results demonstrated that silver ions could be detected by the PDMAM-Au NPs based colorimetric assays, further opening up new ways for the visualization and quantification of silver ions involved in our daily life.展开更多
基金supported by the National Natural Science Foundation of China(6137103921305067+5 种基金21105048)China Postdoctoral Science Foundation Funded Project(2012T50475)Science Foundation of Jiangsu Province(BK20130754)Ph D Fund of the Ministry of Education for Young Teachers(0133219120019)King Saud University(Distinguished Scientist Fellowship Program)Graduate Education Innovation Program of Nanjing University of Science and Technology and Chinese Academy of Sciences
文摘Organophosphorous pesticide(OP) contamination has serious adverse effects on human health and the environment. Due to the toxicity of OPs and the threat presented by their accidental or intentional release in populated areas, the determination and monitoring of these OPs in food products and environment is of great importance. OPs are present in very small quantities and therefore, methods for their detection need to be highly sensitive and selective. Here, we aimed to develop a simple and selective aptamer-based colorimetric assay for the detection of omethoate, which is one of the commonly used OPs. The principle of the assay is that single-stranded DNA(ss DNA)-wrapped gold nanoparticles(Au NPs) are resistant to salt-induced aggregation. By employing an "artificial antibody" organophosphorous pesticide-binding aptamer(OBA) as the recognition element, aptamer-wrapped Au NPs(Au-apta) show high selectivity towards omethoate, resulting in the disconnection of aptamers from Au NPs and the aggregation of Au NPs. As there is a significant color change from the interparticle plasmon coupling during the aggregation of Au NPs, the established assay showed good linearity between 0.1 and 10 μmol/L, with a low detection limit of 0.1 μmol/L. Other OPs such as profenofos, phorate, and isocarbophos would not interfere with the detection of omethoate despite having similar structures. Thus, the colorimetric method shows potential for use in the detection of omethoate in real soil samples.
基金supported by the Ministry of Science and Technology(Grant Nos. 2009CB930000 and 2011CB933201)the National Natural Science Foundation of China (Grant Nos. 20890020, 21025520 and 90813032)+2 种基金the Chinese Academy of Sciences (Grant No. KJCX2-YW-M15)the Fundamental Research Funds for the Central Universities (Grant No.CDJXS10232211)the Ministry of Human Resources and Social Security of China
文摘This review begins with an overview of the appealing properties and various applications of gold nanoparticles, and briefly summarizes recent advances in using unmodified gold nanoparticles to detect different kinds of targets including nucleic acids, proteins, metal ions and small organic molecules. The key point to the unmodified gold nanoparticle-based visual detection assay is to control dispersion and aggregation of colloidal nanoparticles by targets of interest, which usually relies on affinities between gold nanoparticles and targets. The degree of dispersion or aggregation can be visualized through the change of the solution color or the precipitation of nanoparticles from the solution. Thus, the existence of the target molecules can be trans-lated into optical signals and monitored by the naked eye conveniently. Finally, some future prospects of this research field are given.
基金financially supported by the National Natural Science Foundation of China(21205125,21175138)
文摘Herein, a novel probe based on poly(N,N′-methylenebisacylamide) protected Au NPs(PDMAM-Au NPs) was developed for determination of silver ions. The thiol-terminated PDMAM was synthesized by the reversible addition fragmentation chain transfer radical polymerization. Then, the PDMAM-Au NPs were prepared by a simple, one-pot and green process. It has been observed that existence of the silver ions evoked a small red-shift to the emission peak of PDMAM-Au NPs and an obvious increase in UV absorption. The detection limit of the present method for silver ions was 0.5 ?mol/L, with a linear range of 1.0–1000 ?mol/L. Moreover, the possible mechanism for enhanced UV absorption intensity with enlarged diameter of PDMAM-Au NPs was explored and discussed briefly. The results demonstrated that silver ions could be detected by the PDMAM-Au NPs based colorimetric assays, further opening up new ways for the visualization and quantification of silver ions involved in our daily life.
