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Updated: Jun 23, 2026
Fabrication of Electrochemical-DNA Biosensors for the Reagentless Detection of Nucleic Acids, Proteins and Small Molecules
Published on: June 1, 2011
Ultrasensitive electrochemical detection of DNA based on PbS nanoparticle tags and nanoporous gold electrode
Kongcheng Hu1, Ping Liu, Sujuan Ye
1Key Laboratory of Eco-chemical Engineering, Ministry of Education, College of Chemistry and Molecular Engineering, Qingdao University of Science and Technology, Qingdao 266042, PR China.
Abstract:
An electrochemical stripping assay for ultrasensitive detection of target DNA was reported in this work. The protocol involved nanoporous gold (NPG) electrode modified with single-stranded DNA (ssDNA) and Au nanoparticles (Au-NPs) co-loaded with two kinds of ssDNA, one was reporter DNA which was complementary to the target DNA, the other modified with PbS nanoparticles (PbS-NPs) was signal DNA which was non-complemented, reducing the cross-reaction between the targets and reporter DNA on the same Au-NP. The amount of target DNA was determined by indirect determination of the amount of lead ions through differential pulse anodic stripping voltammetry (DPASV). This protocol could detect target DNA of as low as femtomolar and exhibited excellent selectivity against one-base mismatched DNA and non-complementary DNA. Under the optimum conditions, the anodic stripping peak current of lead demonstrated a good linear relationship with the target DNA concentration in the range of 9.0x10(-16) to 7.0x10(-14) M. A detection limit of 2.6x10(-16) M of target DNA was achieved.
