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

Abstract

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.

Recent Development of Implantable Chemical Sensors Utilizing Flexible and Biodegradable Materials for Biomedical Applications

“…Efforts to eliminate the need to retrieve implanted devices have led to the development of bioresorbable glucose sensors. Li et al 34 have developed a fully bioresorbable electrochemical sensor for CGM. As shown in Figure 6c (I), the sensor contained a glucose sensor, a dissolved oxygen (DO) sensor, and a temperature sensor fabricated on a PLGA substrate.…”

“…Zn, W, and Mo are commonly used as electrodes in implantable biodegradable chemical sensors. For example, a fully printed, bioresorbable glucose sensor with a Zn WE, a Mo CE, and a Mo–W RE has been developed for subcutaneous glucose monitoring …”

“…For example, a fully printed, bioresorbable glucose sensor with a Zn WE, a Mo CE, and a Mo−W RE has been developed for subcutaneous glucose monitoring. 34 Fe has been utilized as the sensing or catalytic component in implantable chemical sensors. 32,198 The electrical dissolution rate of Fe is determined to be 7−9 μm/h in Hank's solution at RT.…”

“…(I) Schematic illustration and representative image of the electrochemical sensor; (II) The degradation of the bioresorbable glucose sensor in PBS solution; (III) In vivo evaluations of the bioresorbable electrochemical sensor. Reprinted with permission under a Creative Commons CC BY 4.0 License from ref []. Copyright 2023 American Association for the Advancement of Science.…”

Advances in Bioresorbable Materials and Electronics

“…71 By immobilizing the SPP-PEDOT:PSS electrode with enzymes, such as glucose oxidase (GOx), the same device can function as a glucose sensor. Exploiting similar electrochemical means of sensing, a more recent research report describes continuous glucose monitoring (CGM) using a hybrid device that comprises a wearable control circuit (nonbioresorbable) and a bioresorbable implantable sensor, 194 with screenprinted GOx coated Zn, Mo−W, and Mo as WE, RE, and CE, respectively. An additional Zn sacrificial electrode (SE) compensates effects that occur during slow biodegradation, thereby enabling accurate yet prolonged glucose sensing within a wide range of 0−25 mM (sensitivity = 0.2458 μA mM −1 ) over 5−7 days.…”