title: A simple electrochemical platform based on pectin stabilized gold nanoparticles for picomolar detection of biologically toxic amitrole.
abstract: Amitrole is a biologically toxic nonselective herbicide which contaminates surface and ground waters at unprecedented rates. All reported modified electrodes that detect amitrole within sub-micromolar to nanomolar levels were based on the electro-oxidation of amitrole. Herein, we developed a new conceptual idea to detect picomolar concentrations of amitrole based on calcium cross linked pectin stabilized gold nanoparticle (CCLP-GNP) film modified electrode which was prepared by electrodeposition. When the electrochemical behavior of amitrole was investigated at the CCLP-GNP film, the reduction peak current of the GNPs linearly decreased as the concentration of amitrole increases. We have designed a determination platform based on the amitrole dependent decrease of the GNP cathodic peak. The described concept and high sensitivity of square wave voltammetry together facilitate the great sensing ability; as a result the described approach is able to reach a low detection limit of 36 pM which surpassed the detection limits of existing protocols. The sensor presents a good ability to determine amitrole in two linear concentration ranges: (1) 100 pM-1500 pM with a detection limit of 36 pM; (2) 100 nM-1500 nM with a detection limit of 20 nM. The preparation of CCLP-GNPs is simple, rapid and does not require any reducing agents.
authors.affiliation: Electroanalysis and Bioelectrochemistry Lab, Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, No.1, Section 3, Chung-Hsiao East Road, Taipei 106, Taiwan, Republic of China. smchen78@ms15.hinet.net.
authors.forename: Veerappan
authors.initials: V
authors.lastname: Mani
authors.forename: Rajkumar
authors.initials: R
authors.lastname: Devasenathipathy
authors.forename: Shen-Ming
authors.initials: SM
authors.lastname: Chen
authors.forename: V S
authors.initials: VS
authors.lastname: Vasantha
authors.forename: M
authors.initials: M
authors.lastname: Ajmal Ali
authors.forename: Sheng-Tung
authors.initials: ST
authors.lastname: Huang
authors.forename: Fahad M A
authors.initials: FM
authors.lastname: Al-Hemaid
mesh_terms: D000640:Amitrole / Q000032:analysis* / Q000737:chemistry; D002118:Calcium / Q000737:chemistry; D002623:Chemistry Techniques, Analytical / Q000379:methods*; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry*; D057230:Limit of Detection; D053758:Nanoparticles / Q000737:chemistry*; D010368:Pectins / Q000737:chemistry*
chemical_list: D006046:Gold; D010368:Pectins; D002118:Calcium; D000640:Amitrole