Research Advances and Trends of Rapid Detection Technologies for Pathogenic Bacteria Based on Fingerprint Spectroscopy

Pathogen detection is essential to ensure the safety of drinking water and food, and handle public health emergencies. However, the current testing standards or methods have the defects of labor-intensive, time-consuming operation and high cost, which makes it difficult to meet the requirements of high timeliness in modern society. Therefore, developing rapid detection technology for pathogenic bacteria with simple operation and low-cost is extremely urgent. In recent years, with the rapid development of laser and photoelectric detection technologies, laser-based spectral technologies, which can quickly obtain fingerprint information of microorganism, have attracted wide attention from researchers. Among them, surface enhanced Raman spectroscopy (SERS) and laser induced breakdown spectroscopy (LIBS) with the advantages of rapid, non-destructive or micro-destructive detection in situ have been widely investigated in rapid detection of pathogens. As a molecular vibrational spectroscopy technique, SERS introduces noble metal nanostructures with optical signal amplification capability into conventional Raman spectroscopy, which can enhance the Raman signal order of magnitude while quenching fluorescence, so that the fingerprint spectrum information of the whole bacterial cells can be quickly obtained. However, due to the material, morphology, and size of noble metal nanoparticles and the distance between nanoparticles and the target, reproducibility is still a major bottleneck for SERS in bacterial detection. As an emerging atomic emission spectroscopy technique, LIBS has the capability of real-time detection of multiple elements, and can quickly obtain all element information of samples including micro and trace elements. When using LIBS to classify and identify bacteria, in order to reduce the elemental interference of the substrate and the coexisting matrix, it is necessary to collect a large number of spectral data of pure cultured bacteria, which not only increases the detection period but also lost the quantitative capability at the same time. In view of the research status of SERS and LIBS technology in the rapid detection of pathogenic bacteria, this review summarized the advantages and limitations of the two methods and forecasted their research trends in the fields of bacterial detection, thus providing references for the development of rapid detection techniques for pathogens based on laser spectroscopy.