Ultrasensitive Detection of Cymbidium Mosaic Potexvirus Using a Single-Wall Carbon Nanotube-Functionalized Quartz Crystal Microbalance

Abstract

We have developed an ultrasensitive, convenient, real-time platform for detecting Cymbidium mosaic potexvirus (CymMV) based on single-wall carbon nanotube (SWNT)-functionalized quartz crystal microbalance (QCM) sensors. Functionalization was achieved by coating the QCM electrode with SWNTs, followed by 1,1'-carbonyldiimidazole-activated Tween 20 (CDI-Tween 20) modification and conjugation of antibodies. Sensitivity was enhanced from 2.18 to 11.5 Hz ng(-1) when 0.1 mu g mL(-1) CymMV was applied. The low limit of detection of SWNT-functionalized QCM sensors was improved from 2.08 to 0.502 ng. The SWNT-functionalized QCM sensor was successfully used to quantify the amount of CymMV contained in infected orchid leaves. Compared to enzyme-linked immunosorbent assay (ELISA), SWNT-functionalized QCM sensors are fast, economical, and ultra-sensitive, with comparable sensitivities. The current study demonstrates the application of QCM sensors as a convenient platform to detect and quantify CymMV. (C) 2010 The Japan Society of Applied Physics