Label-Free Colorimetric Detection of Arsenite Utilizing G-/T-Rich Oligonucleotides and Unmodified Au Nanoparticles



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“Free” arsenite sensor: Based on the principle that G-/T-rich single-stranded DNA (ssDNA) and folded DNA bound to arsenite have different propensities to adsorb onto Au nanoparticles (Au NPs) in colloidal solution, a label-free colorimetric assay for arsenite sensing based on color changes associated with the aggregation of Au NPs has been designed (see scheme).