Abstract
Abstract
This work developed a sensitive DNA-based fluorescent probe comprising a cysteine binding unit and a signal amplification unit based on a catalyzed hairpin assembly (CHA) reaction. The cysteine binding unit comprises a homodimer of single-stranded DNA (ssDNA) rich in cytosine and held together by silver ions. In the presence of cysteine, the homodimer is disintegrated because of cysteine-silver binding that liberates the ssDNA, which drives the CHA reaction in the signal amplification unit. Förster resonance energy transfer (FRET) was used to report the generation of the amplified double-stranded DNA (dsDNA) product. Under the optimal conditions, the probe provided a good linearity (100–1200 nM), a good detection limit (47.8 ± 2.7 nM) and quantification limit (159.3 ± 5.3 nM), and a good sensitivity (1.900 ± 0.045 μM−1). The probe was then used to detect cysteine in nine real food supplement samples. All results provided good recoveries that are acceptable by the AOAC, indicating that it has potential for practical applications.
Funder
The Graduate School Research Support Funding for Thesis 2015
The Thailand’s Education Hub for ASEAN Countries (TEH-AC) scholarship
The Thailand Center of Excellence in Physics (ThEP), Prince of Songkla University and Faculty of Science, Prince of Songkla University
The Royal Golden Jubilee Ph.D. Programme by the Thailand Research Fund (TRF), Thailand Science Research and Innovation (TSRI) and National Research Council of Thailand
The Thailand Science Research and Innovation
Subject
Spectroscopy,General Materials Science,Instrumentation,Atomic and Molecular Physics, and Optics