A high-performance wearable microneedle sensor based on a prussian blue-carbon nanotube composite electrode for the detection of hydrogen peroxide and glucose

Hydrogen peroxide (H2O2) plays an important role in biology, and biomarker detection in skin interstitial fluid (ISF) has recently shown great promise. However, limited sensors were designed for H2O2 detection in ISF. Therefore, a high-performance wearable H2O2 microneedle sensor with a Prussian blue (PB)/carbon nanotube (CNT) composite electrode and a glucose microneedle sensor based on this electrode were developed. Two types of H2O2 microneedle sensors with different CNT and PB ratios were prepared with ultra-wide detection ranges (1 μΜ–2800 mM/100 nΜ–2200 mM) in accordance with the Hill equation. Ultra-high sensitivity (954.1 μA mM−1 cm−2 and 451 μA mM−1 cm−2) and excellent linearity (R2=0.999) were exhibited in linear ranges of 1 μM to 10 mM and 100 nM to 10 mM, respectively·H2O2 sensors exhibit good selectivity and essentially unattenuated detection signals in artificial ISF. The glucose enzyme-catalyzed microneedle sensor based on the CNT/PB composite electrode also exhibited a great detection range (0.5 mM–180 mM) in accordance with the Hill equation and ultra-wide linear range (0.5 mM–40 mM) with high sensitivity (16.56 μA mM−1 cm−2) and linearity (R2=0.995) in artificial ISF. To verify the practical applicability of the sensors, H2O2 levels in normal and tumor cells were successfully detected by the H2O2 sensor. The glucose levels in ISF before and after eating were successfully detected by the glucose sensor in vivo. The present work developed a low-cost, easy-to-prepare H2O2 sensor and a related enzyme-catalyzed sensor with excellent performance, which hold promising prospects for application across diverse fields. •Highest sensitivity (954.1 μA mM−1 cm−2) in H2O2 linear range of 1 μM to 10 mM.•Largest H2O2 detection range in accordance with the Hill equation.•The released H2O2 in different cells has been detected.•The glucose changes in human ISF in vivo have been detected.•Suitable combination of composite preparation and hollow microneedle modification.