Interfacial charge regulation of protein blocking layers in transistor biosensor for direct measurement in serum.
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.
['Park|Sungwook|S|', 'Kim|Minsoo|M|', 'Kim|Dongkap|D|', 'Kang|Seok Ho|SH|', 'Lee|Kwan Hyi|KH|', 'Jeong|Youngdo|Y|']
D000818:Animals D000954:Antigens, Surface D015374:Biosensing Techniques D001798:Blood Proteins D002417:Cattle D043425:Glutamate Carboxypeptidase II D006454:Hemoglobins D006801:Humans D009113:Muramidase D040081:Protein Array Analysis D012710:Serum Albumin, Bovine
Protein blocking layer Biosensor Serum Field-effect transistor Non-specific binding