Double-stranded DNA single-walled carbon nanotube hybrids for optical hydrogen peroxide and glucose sensing

The unique optical properties of semiconducting single-walled carbon nanotubes (SWNTs) are exquisitely sensitive to variations in the surrounding environments. Here, we have studied the redox chemistry of SWNTs encased with double-stranded deoxyribonucleic acid (DNA) reacted with either hydrogen peroxide H2O2 or glucose in the presence of the glucose oxidase enzyme. The DNA-SWNT hybrids are prepared in aqueous solution by sonication that cuts the DNA into short fragments of 100-300 base pairs which efficiently wrap individual nanotubes. The DNA-SWNT hybrids are optically sensitive to H2O2 and glucose, and the hybrid surface can be regenerated by dialytically removing the hydrogen peroxide. This study reinforces the potential of DNA-SWNT hybrids for use in immunoassays and glucose sensing.