Detection of Analytes on Arrays/Microarrays/DNA Chips

Microarrays/arrays/DNA chips are frequently being used to detect different analytes in biosensors. This chapter analyzes the detection of different analytes on microarrays/arrays/DNA chips and analyzes the kinetics of binding and dissociation (hybridization) in such biosensors through fractal analysis. Both single- and dual-fractal analysis are used to analyze binding (hybridization) of different targets (400 nM) in solution to a probe immobilized on a DNA chip surface, binding (hybridization) of different concentrations of free-DNA in solution to a 22-mer strand (bound DNA) immobilized via a phenylene-diisocyanate linker molecule on a glass substrate, SA-HRP (streptavidin-horseradish peroxide) in solution to a capture probe on a QCM (quartz crystal microbalance) electrode along with a detection probe, a complementary and a noncomplementary (three-base mismatch strand) DNA in solution to a 30-mer 30-thiolated DNA strand immobilized on an electrochemical enzymatic genosensor, binding (hybridization) of a perfectly matched oligonucleotide (ODN-P) and a noncomplementary ODN (ODN-N) to an electrochemical sensor with an EST2-A34 reporter. Fractal analyses are also used to discuss the binding and dissociation during PNA–DNA hybridization, PNA–DNA hybridization, and binding (hybridization) of different concentrations of ss DNA in solution preincubated with prehybridized 22-nt FQ duplex to a “broken beacon” immobilized on a sensor surface. Fractal analysis can be considered as an alternate method of analyzing the kinetics of binding and dissociation during hybridization in these types of analyte–receptor reactions occurring on biosensor surfaces.