title: Sample preconcentration utilizing nanofractures generated by junction gap breakdown assisted by self-assembled monolayer of gold nanoparticles.
abstract: The preconcentration of proteins with low concentrations can be used to increase the sensitivity and accuracy of detection. A nonlinear electrokinetic flow is induced in a nanofluidic channel due to the overlap of electrical double layers, resulting in the fast accumulation of proteins, referred to as the exclusion-enrichment effect. The proposed chip for protein preconcentration was fabricated using simple standard soft lithography with a polydimethylsiloxane replica. This study extends our previous paper, in which gold nanoparticles were manually deposited onto the surface of a protein preconcentrator. In the present work, nanofractures were formed by utilizing the self-assembly of gold-nanoparticle-assisted electric breakdown. This reliable method for nanofracture formation, involving self-assembled monolayers of nanoparticles at the junction gap between microchannels, also decreases the required electric breakdown voltage. The experimental results reveal that a high concentration factor of 1.5×10(4) for a protein sample with an extremely low concentration of 1 nM was achieved in 30 min by using the proposed chip, which is faster than our previously proposed chip at the same conditions. Moreover, an immunoassay of bovine serum albumin (BSA) and anti-BSA was carried out to demonstrate the applicability of the proposed chip.
authors.affiliation: Department of Mechanical Engineering and Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, Chia Yi, Taiwan, R.O.C.
authors.forename: Chun-Ping
authors.initials: CP
authors.lastname: Jen
authors.affiliation: Laboratory of Experimental Models of Emotional Pathology, Scientific Research Institute of Physiology and Basic Medicine, Novosibirsk, Russia.
authors.forename: Tamara G
authors.initials: TG
authors.lastname: Amstislavskaya
authors.affiliation: Department of Mechanical Engineering and Advanced Institute of Manufacturing with High-Tech Innovations, National Chung Cheng University, Chia Yi, Taiwan, R.O.C.
authors.forename: Kuan-Fu
authors.initials: KF
authors.lastname: Chen
authors.affiliation: Department of Medicine, National Cheng-Kung University, Tainan, Taiwan, R.O.C; Department of Biochemistry and Molecular Biology, National Cheng-Kung University, Tainan, Taiwan, R.O.C.
authors.forename: Yu-Hung
authors.initials: YH
authors.lastname: Chen
mesh_terms: D004129:Dimethylpolysiloxanes / Q000737:chemistry; D006046:Gold / Q000737:chemistry*; D056656:Lab-On-A-Chip Devices; D008567:Membranes, Artificial; D053768:Metal Nanoparticles / Q000737:chemistry*; D011076:Polycarboxylate Cement / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000302:isolation & purification*
chemical_list: D004129:Dimethylpolysiloxanes; D008567:Membranes, Artificial; D011076:Polycarboxylate Cement; C005506:polycarbonate; D012710:Serum Albumin, Bovine; C013830:baysilon; D006046:Gold