Label-Free Immunodetection in High Ionic Strength Solutions Using Carbon Nanotube Transistors with Nanobody Receptors

Proceedings

Filipiak, Marcin S.¹ 

关键词: single-walled carbon nanotube (SWCNT) networks;    field-effect transistor (FET);    Debye screening;    label-free immunosensing;    nanobodies (VHH);    polyethylene glycol (PEG);   

DOI  :  10.3390/proceedings1040491

学科分类：社会科学、人文和艺术（综合）

来源: mdpi

【 摘 要 】

Nanomaterial-based field-effect transistors (FETs) have been proposed for real-time, label-free detection of various biological species. However, screening of the analyte charge by electrolyte ions (Debye screening) has so far limited their use in physiological samples. Here, this challenge is overcome by combining FETs based on single-walled semiconducting carbon nanotube networks (SWCNTs) with a novel surface functionalization comprising: (1) short nanobody receptors, and (2) a polyethylene glycol layer (PEG). Nanobodies are stable, easy-to-produce, short biological receptors (~2–4 nm) that enable analyte binding closer to the sensor surface. The addition of PEG enhances the signal in high ionic strength environment. Using green fluorescent protein (GFP) as a model antigen, high selectivity and sub-picomolar detection limit with a dynamic range exceeding 4 orders of magnitude is demonstrated in physiological solutions. The presented immunoassay is fast, label-free, does not require any sample pre-treatment or washing steps.

【 授权许可】

CC BY