From weak adsorption to selective detection: functionalized interfaces for SERS glucose sensing

Area of Science:

• Analytical Chemistry
• Spectroscopy
• Materials Science

Background:

• Surface-enhanced Raman scattering (SERS) offers sensitive molecular analysis but faces challenges with glucose detection.
• Glucose, a neutral polyol, weakly adsorbs onto noble metal surfaces, hindering effective SERS signal generation.
• The core limitation in SERS glucose sensing is the interfacial mismatch between glucose chemistry and SERS requirements.

Purpose of the Study:

• To review functionalized interfaces as a primary strategy to overcome SERS limitations for glucose sensing.
• To analyze various interface designs, including boronic-acid-centered, biomolecular, and molecularly imprinted approaches.
• To identify design priorities for achieving selective, reproducible, and analytically credible glucose detection via SERS.

Main Methods:

• Discussion of SERS principles relevant to glucose sensing: enhancement mechanisms, distance dependence, adsorption, and matrix effects.
• Analysis of boronic-acid-centered interfaces for reversible cis-diol recognition and adaptable readout.
• Assessment of alternative recognition strategies like biomolecular and molecularly imprinted interfaces.

Main Results:

• Boronic-acid-centered interfaces represent a developed strategy combining recognition, surface attachment, and readout.
• Alternative interfaces offer selectivity but present challenges in distance, stability, transport, or coupling.
• Analytical performance is influenced by receptor chemistry, hotspot proximity, signal conversion, sample handling, and matrix tolerance.

Conclusions:

• Functionalized interfaces are crucial for addressing the interfacial mismatch in SERS glucose sensing.
• Optimizing interface design, including receptor chemistry and hotspot proximity, is vital for analytical performance.
• Framing SERS glucose sensing as an interfacial problem guides the development of reliable glucose detection methods.