DNAzyme@MOF breaking pH limitation for the detection of dopamine in the interstitial fluid

The level of dopamine (DA) in the human body has a certain correlation with neurological diseases. However, most detection methods of DA are complex and expensive. In this study, laccase-like DNAzyme@MOF with improved pH stability was successfully prepared. DNAzyme@MOF could catalyze the chromogenic substrate to change the color of the solution for the detection of DA in ISF. The addition of DNAzyme made DNAzyme@MOF possess higher stability and enzyme-like activity. The operation process was simple, rapid, and intuitive. In addition, the in vivo DA content in skin interstitial fluid (ISF) was analyzed by an off-line method. The swelling hydrogel microneedles (MNs) were prepared to extract skin ISF. DA in skin ISF was recovered and detected by laccase-like DNAzyme@MOF. This study realized the minimally invasive detection of DA. The proposed detection method of biomarkers in ISF based on DNAzyme@MOF would provide a new dimension towards the future development for the detection of other biomarkers in ISF.