CRISPR/Cas12a system responsive DNA hydrogel for label-free detection of non-glucose targets with a portable personal glucose meter.

In this work, personal glucose meter (PGM) as a portable electrochemical device was utilized for sensitive detection of non-glucose targets: N-gene and PCB77, respectively. DNA hydrogel, which can respond to CRISPR/Cas system, was prepared for label-free encapsulating invertase. In the presence of targets, the repeated sequence for the activation of Cas12a was obtained due to the performance of RCA. Unlike "one-to-one" recognition, activated Cas12a can efficiently cleave multiple single-stranded linker DNAs on DNA hydrogels, thus releasing many invertase that can be used for PGM detection. With the amplification of RCA and CRISPR/Cas system, high detection sensitivity can be obtained even using portable PGM. The detection limits for N-gene and PCB77 were 2.6 fM and 3.2 × 10−5 μg/L, respectively, with high specificity and good practical application performance. The developed biosensor can be used for online monitoring with the merit of low cost, easy operation and can be used for various targets analysis. A label-free strategy for CRISPR/Cas12a triggered portable PGM sensor was developed for the detection of N-gene and PCB77 using DNA hydrogel encapsulating invertase. [Display omitted] • Portable personal glucose meter was used to detect non-glucose targets. • DNA hydrogel was prepared for label-free encapsulating invertase. • CRISPR/Cas system can efficiently destroy DNA hydrogel and release invertase. • The same crRNA can be used to detect different targets. [ABSTRACT FROM AUTHOR]