Park, Sungwook Kim, Minsoo Kim, Dongkap Kang, Seok Ho Lee, Kwan Hyi Jeong, Youngdo 2024-01-19T18:30:51Z 2024-01-19T18:30:51Z 2021-09-05 2020-01-01 0956-5663 https://pubs.kist.re.kr/handle/201004/119103 Ion-sensitive field-effect transistor (ISFET) as a biosensor facilitates a process of data-acquisition through label-free and real-time monitoring. Direct quantification of a biomarker in serum is challenging in ISFET biosensor since charged proteins in serum interfere transduction to electrical signals. Here, we report the fabrication of protein blocking layers (PBLs) with intended interfacial charges to minimize non-specific protein bindings on ISFET. Use of charged protein precursors enables to regulate the interfacial charge of PBLs, preserving their intrinsic electric features (neutral: hemoglobin, positively charged: lysozyme, negatively charged: BSA). The effect of this interfacial charge on the signal was demonstrated through PSMA (prostate cancer biomarker) sensing using a dual-gate ISFET biosensor. The neutral PBL showed the minimum noise compared to the negatively and positively charged PBLs, enabling the ISFET to exhibit the same detection range in untreated serum as with pre- or post-treatment (1 fg/ml to 100 ng/ml). The introduction of neutral PBLs to ISFET biosensors would allow the application of the ISFET biosensor as a point-of-care device. English ELSEVIER ADVANCED TECHNOLOGY FIELD-EFFECT TRANSISTOR LABEL-FREE GOLD NANOPARTICLES TUMOR-MARKER INSULIN Interfacial charge regulation of protein blocking layers in transistor biosensor for direct measurement in serum Article 10.1016/j.bios.2019.111737 1 BIOSENSORS & BIOELECTRONICS, v.147 BIOSENSORS & BIOELECTRONICS 147 scie scopus 000498753800022 2-s2.0-85073682790 Biophysics Biotechnology & Applied Microbiology Chemistry, Analytical Electrochemistry Nanoscience & Nanotechnology Biophysics Biotechnology & Applied Microbiology Chemistry Electrochemistry Science & Technology - Other Topics Article FIELD-EFFECT TRANSISTOR LABEL-FREE GOLD NANOPARTICLES TUMOR-MARKER INSULIN Protein blocking layer Field-effect transistor Serum Non-specific binding Biosensor