Detection involving the use of Au-NPs as carriers

Au-NPs can be used as nanocarriers for other NPs or other electroactive species. As a result, the DNA detection is notably enhanced compared to the use of single labels. However, this strategy requires a careful work to avoid irreproducibility in the biosensors response [27]. 

Analyte Modified Electrode Substrate Detection Technique Detection Limit Reference 

AuE gold electrode DPV differential pulse voltammetry EIS electrochemical impedance spectroscopy GCE glassy carbon electrode (Ru(NH3)sL pentaamin ruthenium [3-(2-phenanthren-9-yl-vinyl)-pyridine] complex. 

Bio-bar code technique was also employed by Shen et al. [16] with an electrochemical DNAzyme biosensor. The DNAzyme hybridizes to a specially designed complementary substrate strand that has an overhang, which in turn hybridizes to the DNA-Au bio-bar code (short oligonucleotides attached to 13-nm gold nanoparticles). Upon binding of Pb + to the DNAzyme, the DNAzyme 

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