碳纳米管
纳米技术
材料科学
德拜长度
生物传感器
晶体管
信号(编程语言)
钝化
光电子学
计算机科学
化学
工程类
电气工程
离子
电压
程序设计语言
有机化学
图层(电子)
作者
Faris Albarghouthi,Daria Semeniak,Iman Khanani,James L. Doherty,Barbara Herrnstein Smith,Matthew Salfity,Quentin MacFarlane,Aneesh Karappur,Steven Noyce,Nicholas X. Williams,Daniel Y. Joh,Joseph Andrews,Ashutosh Chilkoti,Aaron D. Franklin
出处
期刊:ACS Nano
[American Chemical Society]
日期:2024-02-09
标识
DOI:10.1021/acsnano.3c11679
摘要
Electrical biosensors, including transistor-based devices (i.e., BioFETs), have the potential to offer versatile biomarker detection in a simple, low-cost, scalable, and point-of-care manner. Semiconducting carbon nanotubes (CNTs) are among the most explored nanomaterial candidates for BioFETs due to their high electrical sensitivity and compatibility with diverse fabrication approaches. However, when operating in solutions at biologically relevant ionic strengths, CNT-based BioFETs suffer from debilitating levels of signal drift and charge screening, which are often unaccounted for or sidestepped (but not addressed) by testing in diluted solutions. In this work, we present an ultrasensitive CNT-based BioFET called the D4-TFT, an immunoassay with an electrical readout, which overcomes charge screening and drift-related limitations of BioFETs. In high ionic strength solution (1X PBS), the D4-TFT repeatedly and stably detects subfemtomolar biomarker concentrations in a point-of-care form factor by increasing the sensing distance in solution (Debye length) and mitigating signal drift effects. Debye length screening and biofouling effects are overcome using a poly(ethylene glycol)-like polymer brush interface (POEGMA) above the device into which antibodies are printed. Simultaneous testing of a control device having no antibodies printed over the CNT channel confirms successful detection of the target biomarker via an on-current shift caused by antibody sandwich formation. Drift in the target signal is mitigated by a combination of: (1) maximizing sensitivity by appropriate passivation alongside the polymer brush coating; (2) using a stable electrical testing configuration; and (3) enforcing a rigorous testing methodology that relies on infrequent DC sweeps rather than static or AC measurements. These improvements are realized in a relatively simple device using printed CNTs and antibodies for a low-cost, versatile platform for the ongoing pursuit of point-of-care BioFETs.
科研通智能强力驱动
Strongly Powered by AbleSci AI