Two-dimensional polymeric cobalt phthalocyanine synthesized by microwave irradiation and its use for continuous glucose monitoring

Two-dimensional polymeric cobalt phthalocyanine (poly-CoPc) was synthesized using a microwave-assisted process, and its feasibility for use in continuous glucose monitoring (CGM) was investigated. The poly-CoPc/CNT composite showed 18% higher Co content than using commercial CoPc (c-CoPc/CNT) and synthesized CoPc (s-CoPc/CNT) composites, due to its intrinsic polymeric structure. In the cyclic voltammetry test, the bioelectrode incorporating glucose oxidase (GOx) based upper enzyme layer ([poly-CoPc/CNT]/PEI/[GOx-TPA]) demonstrated 1.51 times higher current densities than monomeric CoPc used bioelectrode ([CoPc/CNT]/PEI/[GOx-TPA]). This improvement is attributed to the higher biocompatibility with the enzyme layer of poly-CoPc, which prevents the blocking of hydrophobic sites near the co-factor of GOx. As a glucose sensor, [poly-CoPc/CNT]/PEI/[GOx-TPA] exhibits a sensitivity of 50.5 µA mM −1 cm −2 and a response time of 2.4 s in the chronoamperometric response test. Furthermore, the proposed bioelectrode showed 95.6% performance maintenance during 24 h and 81.4% stability over 20 days. These findings demonstrate the suitability of [poly-CoPc/CNT]/PEI/[GOx-TPA] for implantable and low-invasive patch-type glucose sensors offering high sensitivity, durability, and a linear response within the physiological glucose concentration range (0.1–20.0 mM) of both average individuals and diabetic patients.