Colorimetric logic gates for small molecules using split/integrated aptamers and unmodified gold nanoparticlest

摘要

Herein we report the "OR" and "AND" colorimetric logic gates for small molecules using split/integrated aptamers and unmodified gold nanoparticles, which generate visually observed outputs according to Boolean operations. Recently, DNA-based logic gates which generate responses to the inputs according to Boolean operations have attracted researchers' attention.1 Several DNA-based logic gates have been constructed, most of which rely on fluorescent signal outputs.2 By contrast, colorimetric signal outputs can be visually distinguished or easily monitored via UV-vis absorption spectra.3 Especially, the incorporation of DNA oligonucleotides and gold nanoparticles (AuNPs) has been used in the design of colorimetric logic gates,4 which exploits the recognition ability of oligonucleotides and the unique optical properties of AuNPs. Such incorporation has been well developed in identifying a variety of single targets, either by using the DNA-modified AuNPs5 or the unmodified AuNPs.6 For those reported colorimetric logic gates based on DNA and AuNPs,4 however, the modification of DNA onto AuNPs is usually required. In comparison, the use of unmodified AuNPs can