Colorimetric Glucose Detection Using Copper Complexes and Filter Paper-Based Simulated Skin Analysis: Influence of...

Area of Science:

• Coordination Chemistry
• Chemical Sensing
• Biomaterials

Background:

• Schiff base ligands are crucial in synthesizing metal complexes with diverse applications.
• Copper complexes have shown promise as catalysts and sensors.
• Glucose sensing is vital for diabetes management and requires sensitive, accessible methods.

Purpose of the Study:

• To synthesize and characterize novel copper complexes ([Cu2LA(OAc)2] and [Cu2LB(OAc)2]) using Schiff base ligands.
• To investigate the potential of these copper complexes as colorimetric sensors for glucose detection via a cascade reaction.
• To evaluate the catalytic activity and mechanistic aspects of the copper complexes for glucose sensing.

Main Methods:

• Synthesis of copper complexes using Schiff base ligands (H2LA and H2LB).
• Colorimetric glucose sensing assay involving glucose oxidase (GOx), H2O2, and o-phenylenediamine (OPD).
• Optimization of reaction conditions (incubation time, pH) and determination of Michaelis constants (Km).
• Mechanistic studies including hydroxyl radical generation assessment and DFT calculations.
• Fabrication of porous microneedles with simulated skin for glucose monitoring.

Main Results:

• Copper complexes 1 and 2 were successfully synthesized.
• The complexes exhibited catalytic activity as colorimetric sensors for glucose detection through a cascade reaction.
• Optimized conditions yielded Michaelis constants (Km) comparable to enzymatic systems.
• Mechanistic studies indicated hydroxyl radical generation as key to catalytic activity.
• A prototype device using microneedles showed a visible color change (white to yellow) with varying glucose concentrations.

Conclusions:

• The synthesized copper complexes function as effective colorimetric sensors for glucose.
• The cascade reaction mechanism involving GOx and H2O2 enables sensitive glucose detection.
• The developed system offers a promising platform for noninvasive, visually detectable glucose monitoring.
• The study demonstrates the potential of tailored copper complexes in developing advanced biosensing technologies.