Immobilization of glucose oxidase on plasma-treated polyethylene for non-invasive glucose detection

Fully printed and self-compensated bioresorbable electrochemical devices based on galvanic coupling for continuous glucose monitoring

Real-time glucose monitoring conventionally involves non-bioresorbable semi-implantable glucose sensors, causing infection and pain during removal. Despite bioresorbable electronics serves as excellent alternatives, the bioresorbable sensor dissolves in aqueous environments with interferential biomolecules. Here, the theories to achieve stable electrode potential and accurate electrochemical detection using bioresorbable materials have been proposed, resulting in a fully printed bioresorbable electrochemical device. The adverse effect caused by material degradation has been overcome by a molybdenum-tungsten reference electrode that offers stable potential through galvanic-coupling and self-compensation modules. In vitro and in vivo glucose monitoring has been conducted for 7 and 5 days, respectively, followed by full degradation within 2 months. The device offers a glucose detection range of 0 to 25 millimolars and a sensitivity of 0.2458 microamperes per millimolar with anti-interference capability and biocompatibility, indicating the possibility of mass manufacturing high-performance bioresorbable electrochemical devices using printing and low-temperature water-sintering techniques. The mechanisms may be implemented developing more comprehensive bioresorbable sensors for chronic diseases.

Co-immobilized bienzyme of horseradish peroxidase and glucose oxidase on dopamine-modified cellulose-chitosan composite beads as a high-efficiency biocatalyst for degradation of acridine

Co-immobilized bienzyme biocatalysts are attracting increasing interest in the field of wastewater treatment due to their widespread application. In this study, we successfully prepared a co-immobilized bienzyme biocatalyst by immobilizing horseradish peroxidase (HRP) and glucose oxidase (GOD) on dopamine (DA) modified cellulose (Ce)-chitosan (Cs) composite beads via covalent binding, designated as Ce-Cs@DA/HRP-GOD beads, and found that the bienzyme biocatalyst had a good ability to catalytically degrade acridine in wastewater. SEM, EPR, FTIR, and XRD were used to characterise the structure and properties of the Ce-Cs@DA/HRP-GOD beads. The co-immobilized bienzyme biocatalyst with a small amount of HRP exhibited better degradation efficiency for acridine (99.5%, 8 h) in simulated wastewater compared to the Ce-Cs@DA/HRP (93.8%, 8 h) and Ce-Cs@DA/GOD (15.8%, 8 h) beads alone. In addition, a reusability study showed that the co-immobilized bienzyme biocatalyst maintained a degradation rate of 61.2% after six cycles of acridine degradation. The good biodegradability and reusability of the biocatalyst might be due to the synergistic effect of bienzyme HRP-GOD, including the strong covalent bonding. Accordingly, the co-immobilized bienzyme biocatalyst based on the cascade reaction may pave the way for efficient and eco-friendly treatment of industrial wastewater.