title: Bifunctional tri(ethylene glycol) alkanethiol monolayer modified gold electrode for on-chip electrochemical immunoassay of pg level leptin.
abstract: An on-chip enzyme-linked immunosorbent assay combined with an electrochemical detection method (EC-ELISA) was employed to detect a leptin, one of the most important adipose derived hormones, using gold electrodes modified with a tri(ethylene glycol) terminated short alkanethiol (TEGCnSH, Cn = (CH(2))n, n = 2, 4, 6, and 8) monolayer. These TEGCnSH monolayers on gold electrodes can suppress non-specific protein adsorption without affecting the electrochemical activity required for detecting p-aminophenol (PAP), which is an alkaline phosphatase (ALP) product. We measured leptin with a highly sensitive detection range (100 pg mL(-1) to 10 ng mL(-1) level) and with the desired detection limit (13.6 pg mL(-1)) by using electrochemical detection. For detecting leptin, the EC-ELISA method using TEGC4SH modified gold electrode with a poly(dimethylsiloxane) based microchannel was superior to the conventional ELISA method. With the EC-ELISA method, we were able to measure leptin with a satisfactory detection range and a pg level detection limit within 30 min, which is a much lower detection level than that obtained with conventional plate based ELISA.
authors.affiliation: National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nishimura
authors.forename: Yukari
authors.initials: Y
authors.lastname: Sato
authors.forename: Mutsuo
authors.initials: M
authors.lastname: Tanaka
authors.forename: Ryoji
authors.initials: R
authors.lastname: Kurita
authors.forename: Kohei
authors.initials: K
authors.lastname: Nakamoto
authors.forename: Osamu
authors.initials: O
authors.lastname: Niwa
mesh_terms: D000473:Alkanes / Q000737:chemistry*; D004129:Dimethylpolysiloxanes / Q000737:chemistry; D004563:Electrochemistry; D004566:Electrodes; D004797:Enzyme-Linked Immunosorbent Assay; D006046:Gold / Q000737:chemistry*; D007118:Immunoassay / Q000295:instrumentation / Q000379:methods*; D020738:Leptin / Q000032:analysis*; D008567:Membranes, Artificial; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D015394:Molecular Structure; D011092:Polyethylene Glycols / Q000737:chemistry*; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D000473:Alkanes; D004129:Dimethylpolysiloxanes; D020738:Leptin; D008567:Membranes, Artificial; D013438:Sulfhydryl Compounds; C028914:triethylene glycol; D011092:Polyethylene Glycols; C013830:baysilon; D006046:Gold