Peptide aptamer-modified single-walled carbon nanotube-based transistors for high-performance biosensors

Abstract

Biosensors employing single-walled carbon nanotube field-effect transistors (SWCNT FETs) offer ultimate sensitivity. However, besides the sensitivity, a high selectivity is critically important to distinguish the true signal from interference signals in a non-controlled environment. This work presents the first demonstration of the successful integration of a novel peptide aptamer with a liquid-gated SWCNT FET to achieve highly sensitive and specific detection of Cathepsin E (CatE), a useful prognostic biomarker for cancer diagnosis. Novel peptide aptamers that specifically recognize CatE are engineered by systemic in vitro evolution. The SWCNTs were firstly grown using the thermal chemical vapor deposition (CVD) method and then were employed as a channel to fabricate a SWCNT FET device. Next, the SWCNTs were functionalized by noncovalent immobilization of the peptide aptamer using 1-pyrenebutanoic acid succinimidyl ester (PBASE) linker. The resulting FET sensors exhibited a high selectivity (no response to bovine serum albumin and cathepsin K) and label-free detection of CatE at unprecedentedly low concentrations in both phosphate-buffered saline (2.3 pM) and human serum (0.23 nM). Our results highlight the use of peptide aptamer-modified SWCNT FET sensors as a promising platform for near-patient testing and point-of-care testing applications.

Different Approaches to Develop Nanosensors for Diagnosis of Diseases

“…Carbon nanotubes (CNT) and nanowires (NW) have been used in FETs. [156][157][158][159][160] In a usual FET, the conductance is depended on the gate voltage. The gate voltage dependence of a FET is achieved by using n-or p-doped semiconductors.…”

“…[157,158] The cancer biomarker cathepsin E was detected with concentrations low as 10 ng/ml in diluted human serum using cathepsin E binding aptamer functionalized CNT-FETs. [160] However, maintaining the semiconductor property of CNT during growth and surface modification was very difficult, making NW a promising alternative. [159,161] The application of NW is versatile [162] and label-free NW have been reported to detect nucleic acids, [163] neurotransmitter (e.g., -aminobutyric acid, a Parkinson's disease, Figure 16.…”

A review of BioFET’s basic principles and materials for biomedical applications

“…Apart from this, Fig. 1b shows examples of various diseases and biomarkers that BioFET can be used as diagnostic of monitoring sensors [5][6][7][8]. To sum up, the BioFETs can have high sensitivity and selectivity without any labeling and high-cost production.…”

Effects of Water and Different Solutes on Carbon‐Nanotube Low‐Voltage Field‐Effect Transistors

“…[ 3 ] In recent years, semiconducting carbon nanotubes have found applications in novel high performance electronics [ 4,5 ] as well as in the emerging field of biosensors. [ 6–9 ] However, as highlighted in a recent review on carbon nanotube chemical sensors, selectivity in such sensors remains poorly understood, and thus presents an important challenge. [ 10 ]…”