Polysilicon nanogap lab-on-chip facilitates multiplex analyses with single analyte
By Sharma Rao Balakrishnan and U. Hashim and Subash C.B. Gopinath and P. Poopalan and H.R. Ramayya and P. Veeradasan and R. Haarindraprasad and A.R. Ruslinda
Published in Biosensors and Bioelectronics
2016
Abstract
Rationally designed biosensing system supports multiplex analyses is warranted for medical diagnosis to determine the level of analyte interaction. The chemically functionalized novel multi-electrode polysilicon nanogap (PSNG) lab-on-chip is designed in this study, facilitates multiplex analyses for a single analyte. On the fabricated 69 nm PSNG, biocompatibility and structural characteristics were verified for the efficient binding of Human Chorionic Gonadotropin (hCG). With the assistance of microfluidics, hCG sample was delivered via single-injection to 3-Aminopropyl(triethoxy)silane (APTES) and Glycidoxypropyl(trimethoxy)silane (GPMS) modified \PSNG\ electrodes and the transduced signal was used to investigate the dielectric mechanisms for multiplex analyses. The results from amperometric response and impedance measurement delivered the scale of interaction between anti-hCG antibody and hCG that exhibited 6.5 times higher sensitivity for the chemical linker, \APTES\ than GPMS. Under optimized experimental conditions, \APTES\ and \GPMS\ modified immunosensor has a limit of detection as 0.56 mIU/ml and 2.93 mIU/ml (at S/N=3), with dissociation constants (Kd) of 5.65