Proton-ELISA: Electrochemical immunoassay on a dual-gated ISFET array

Publication date: 15 October 2018
Source:Biosensors and Bioelectronics, Volume 117
Author(s): Duane S. Juang, Ching-Hui Lin, Yi-Ren Huo, Chia-Yu Tang, Chun-Ren Cheng, Hua-Shu Wu, Shih-Fen Huang, Alexander Kalnitsky, Chun-Cheng Lin
Here we report an electrochemical immunoassay platform called Proton-ELISA (H-ELISA) for the detection of bioanalytes. H-ELISA uniquely utilizes protons as an immunoassay detection medium, generated by the enzyme glucose oxidase (GOx) coupled with Fenton's reagent in a proton amplification reaction cascade that results in a highly amplified signal. A proton-sensitive dual-gated ion-sensitive field effect transistor (DG-ISFET) sensor was also developed for sensitive and accurate detection of the proton signal in H-ELISA. The DG-ISFET sensor comprises of a 128 × 128 array of 16,384 sensing transistors each with an individually addressable back gate to allow for a very high signal throughput and improved accuracy. We then demonstrated that the platform could detect C-reactive protein and immunoglobulin E down to concentrations of 12.5 and 125 pg/mL, respectively. We further showed that the platform is compatible with complex biological sample conditions such as human serum, suggesting that the platform is sufficiently robust for potential diagnostic applications.

Graphical abstract

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