Introduction
Trace liquid analysis is crucial in fields such as biomedical diagnosis, environmental monitoring, and chemical process control. Traditional detection technologies often face bottlenecks including insufficient sensitivity, bulky equipment, and complex operations. Surface-Enhanced Raman Scattering (SERS) technology has emerged as a powerful tool for trace detection due to its molecular fingerprint identification capability. However, conventional SERS suffers from limitations such as low signal collection efficiency and intricate calibration procedures. The innovative integration of optical waveguide and SERS technologies, combined with cutting-edge approaches like artificial intelligence and femtosecond laser processing, has led to the development of ultra-sensitive, portable detection platforms. This integration enables a transformative shift from laboratory-based analysis to on-site real-time monitoring, revolutionizing trace liquid detection.
Recently, a research team led by Associate Researcher Danheng Gao from Haoran Meng's group at the State Key Laboratory of Advanced Manufacturing for Optical Systems, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences (CIOMP), in collaboration with Professor Xinghua Yang from Harbin Engineering University and other teams, published a review article titled " Emerging frontiers in SERS-integrated optical waveguides: advancing portable and ultra-sensitive detection for trace liquid analysis " in Light: Science & Applications . This study systematically reviews the development trajectory of SERS-integrated optical waveguide technology, delves into key research directions including waveguide structure design, sensing interface optimization, and integration of emerging technologies, and focuses on analyzing two major technical pathways: remote sensing probes and microfluidic sensing platforms. It provides comprehensive references for the development of next-generation ultra-sensitive detection technologies. Danheng Gao from CIOMP is the first author of the paper, while Meng Luo and Haoran Meng are the corresponding authors.
1. SERS-Optical Waveguide Integration: Breaking the Bottlenecks of Traditional Detection
Conventional SERS technology relies on the Localized Surface Plasmon Resonance (LSPR) effect of noble metal nanostructures to enhance Raman signals. However, its detection performance is limited by issues such as mismatched excitation and collection efficiency, and complex sample handling. Optical waveguides, with their advantages of mechanical flexibility, electromagnetic interference resistance, and strong light field confinement capabilities, form a perfect complement to SERS technology. Through waveguide-mediated light-matter interactions, they achieve dual improvements: efficient excitation of analytes and enhanced collection of scattered signals.
Core Integration Mechanisms
The integration of optical waveguides and SERS is primarily accomplished through two core pathways:
Key Performance Improvements
As shown in Fig. 2, this integrated technology has significantly overcome the limitations of traditional detection:
2. Technical Innovation Pathways: From Structural Design to Performance Optimization
The development of SERS-integrated optical waveguide technology has always centered on structural innovation and performance improvement, forming a multi-dimensional and multi-level technical system.
Iterative Upgrades of Remote Sensing Probes
Early approaches involving functional modification of SERS substrates on optical fiber end faces enabled remote detection but suffered from issues such as small sensing areas and insufficient signal stability. Research teams have continuously made breakthroughs through structural optimization:
Technological Breakthroughs in Microfluidic Optical Waveguide Platforms
The emergence of microstructured optical waveguides has driven the development of SERS detection towards microfluidic integration, enabling automated analysis of trace samples:
3. Empowerment by Emerging Technologies: Advancing Towards Practical Detection Heights
To further enhance detection performance and promote technology implementation, research teams have deeply integrated SERS-optical waveguide integration technology with emerging methods such as femtosecond laser processing, cavity enhancement technology, and artificial intelligence, addressing challenges in structure fabrication and signal analysis faced by traditional methods.
Breakthroughs in Advanced Fabrication Technologies
Innovations in Signal Enhancement and Analysis
4. Application Scenarios and Future Prospects
SERS-integrated optical waveguide technology has demonstrated great application potential in multiple fields:
Despite significant progress in research and applications, several challenges remain: high manufacturing costs of special-structured optical waveguides, insufficient detection specificity for complex matrix samples, and the need for further optimization of long-term stability and repeatability. Future research will focus on three key directions:
Light Science & Applications
Emerging frontiers in SERS-integrated optical waveguides: advancing portable and ultra-sensitive detection for trace liquid analysis