Carbon-based SERS biosensor: from substrate design to sensing and bioapplication

The sensing of bioactive molecules based on photochemical techniques has become one of the fastest-growing scientific fields. Surface-enhanced Raman scattering (SERS) is a highly sensitive technique for the detection of low-concentration molecules, including DNA, microRNA, proteins, blood, and bacteria; single-cell detection and identification; bioimaging; and disease diagnosis, providing abundant structural information for biological analytes. One rapidly developing field of SERS biosensor design is the use of carbon-based nanomaterials as substrate materials, such as zero-dimensional carbon quantum dots, one-dimensional carbon nanotubes, two-dimensional graphene, and graphene oxide (GO) and three-dimensional spatial carbon nanomaterials or carbon-based core-shell nanostructures. In this review, we describe the recent developments in SERS biosensors, in particular carbon-based SERS, for the detection of bioactive molecules. We systematically survey recent developments in carbon nanomaterial-based SERS biosensors, focusing on fundamental principles for carbon-based materials for SERS biosensor design, fabrication, and operation, and provide insights into their rapidly growing future potential in the fields of biomedical and biological engineering, in situ analysis, quantitative analysis, and flexible photoelectric functional materials. As such, this review can play the role of a roadmap to guide researchers toward concepts that can be used in the design of next-generation SERS biosensors while also highlighting current advancements in this field. Biosensors: Photochemical detection using carbon-based nanomaterialsThe various sheets, tubes, and dot-like nanostructures formed by carbon atoms can make a molecular sensing technology safer and more effective. In surface-enhanced Raman spectroscopy (SERS), detection of single molecules is achieved by attaching biological targets to signal-boosting substrates, typically metal nanoparticles. Biao Kong from Fudan University in Shanghai, China, and colleagues review how metal SERS substrates are being replaced by carbon-based nanostructures engineered to produce localized 'hotspots' where electric fields are enhanced. These substrates offer improved biocompatibility and customizable device structures. For example, graphene can easily host tumor cells for cancer sensing, while carbon dots can attach to DNA strands to act as ultra-small barcodes. The favorable mechanical properties of carbon also enable production of innovative materials including drug-sensing nanosheets that adhere to the surfaces of banknotes and coins. In this review, recent developments of carbon nanomaterial-based SERS biosensors are systematically summarized, which focus on fundamental principles for carbon-based materials for SERS biosensor design, fabrication methods and operation mechanisms, providing insight into their rapidly growing future potential in the fields of biomedical and biological engineering, in-situ analysis, quantitative analysis and flexible photoelectric functional materials.

Automated summary

Photochemical detection of bioactive molecules using carbon-based nanomaterials, such as carbon quantum dots, carbon nanotubes, graphene, and carbon-based core-shell nanostructures, has become a rapidly developing field in biomedical and biological engineering. These materials offer high sensitivity, abundant structural information, and potential applications in in situ analysis, quantitative analysis, and flexible photoelectric functional materials.