Jang, Hyun-June Ahn, Junhyoung Kim, Min-Gon Shin, Yong-Beom Jeun, Minhong Cho, Won-Ju Lee, Kwan Hyi 2024-01-20T07:34:13Z 2024-01-20T07:34:13Z 2021-09-05 2015-02-15 0956-5663 https://pubs.kist.re.kr/handle/201004/125762 Optical laboratory-based immunoassays, such as enzyme-linked immunosorbent assay (ELISA) give a high sensitivity and specificity of various fatal diseases. However, these assays are no longer efficient in on-spot diagnostics of wide-spreading and contagious infections. At this point in time, portable and handhold devices play a pivotal role in infectious diseases with quick diagnostics at or near the site of the disease propagation. In this paper, we demonstrated a novel electrical immunoassay of ELISA that was not based on optical signaling but on electrical signaling. This was done by combining an ion-sensitive field-effect transistor (ISFET) with ELISA. By harnessing the catalytic reaction of alkaline phosphatase that precipitated silver particles, we effectively overcame the chronic Debye screening length issue of the ISFET. Ultimately, small signal ranging from 1 pg/mL to 10 ng/mL was immensely amplified with the ALP label, regardless of buffer conditions. The sensor platform herein surpassed a sensing capability of conventional ELISA that is considered to have a LOD on the order of similar to 1 ng/mL. The results were compared with those of horseradish peroxidase label, which is generally used for optical analyses in ELISA. Our newly developed ISFET-based portable sensor holds a large potential for point-of-care tools in a variety of diseases, without being limited by the need for expensive equipment such as spectro-photometers. (C) 2014 Elsevier B.V. All rights reserved. English ELSEVIER ADVANCED TECHNOLOGY SILVER NANOPARTICLES AMYLOID-BETA HUMAN SERUM THIN-FILM IMMUNOSENSOR ENHANCEMENT PERFORMANCE BIOMARKERS BIOSENSOR GRAPHENE Electrical signaling of enzyme-linked immunosorbent assays with an ion-sensitive field-effect transistor Article 10.1016/j.bios.2014.09.020 1 BIOSENSORS & BIOELECTRONICS, v.64, pp.318 - 323 BIOSENSORS & BIOELECTRONICS 64 318 323 scie scopus 000345059100047 2-s2.0-84907538721 Biophysics Biotechnology & Applied Microbiology Chemistry, Analytical Electrochemistry Nanoscience & Nanotechnology Biophysics Biotechnology & Applied Microbiology Chemistry Electrochemistry Science & Technology - Other Topics Article SILVER NANOPARTICLES AMYLOID-BETA HUMAN SERUM THIN-FILM IMMUNOSENSOR ENHANCEMENT PERFORMANCE BIOMARKERS BIOSENSOR GRAPHENE Immunosensor Point-of-care device ISFET ELISA ALP