title: Immobilization-free multiplex electrochemical DNA and SNP detection.
abstract: A novel electrochemical method for multiplex detection of sequence-specific DNA and single nucleotide polymorphism (SNP) that requires no probe immobilization is reported. The immobilization-free detection of target DNA is realized by the use of a neutrally charged peptide nucleic acid (PNA) probe labeled with an electroactive indicator and a negatively charged ITO electrode. Upon hybridization between the target DNA and the complementary PNA probe, electrostatic repulsion between the negative backbone of the DNA/PNA duplex and the negative surface of the ITO electrode prevents the electroactive indicator from approaching the electrode, resulting in a significantly suppressed electrochemical signal. Multiplex DNA or SNP detection is enabled by using multiple PNA probes with different sequences labeled with different distinguishable electroactive indicators. Due to the immobilization-free nature of this detection scheme, no interference is found between the simultaneous detection of multiple target DNAs or SNPs. This simple and robust immobilization-free multiplex DNA and SNP detection strategy may find applications in a wide range of fields especially in point-of-care testing.
authors.affiliation: The Hong Kong University of Science and Technology, Kowloon, Hong Kong.
authors.forename: Xiaoteng
authors.initials: X
authors.lastname: Luo
authors.forename: I-Ming
authors.initials: IM
authors.lastname: Hsing
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D004247:DNA / Q000032:analysis* / Q000235:genetics*; D004252:DNA Mutational Analysis / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D020411:Oligonucleotide Array Sequence Analysis / Q000295:instrumentation*; D020641:Polymorphism, Single Nucleotide / Q000235:genetics*
chemical_list: D004247:DNA