In this work, we have developed a kind of single-layer graphene-based surface plasmon resonance (SLG-SPR) biosensor to detect C-reactive protein (CRP) and Prostate-specific antigen (PSA). In the experiment of testing CPR, the results obtained revealed that the changes in resonance wavelength of SLG-SPR biosensors are higher than that of the gold-film based SPR (Au-SPR) biosensors. Moreover, for the experiment of testing PSA, due to the dynamic evanescent field enhancement produced by a strong electric field coupling between the localized SPR (LSPR) of AuNPs and SPR of single-layer graphene-based film (SLG-film) that further amplify the evanescent field signal. We verified the SLG-SPR biosensors exhibited higher sensitivity than the Au-SPR biosensors and the SLG-SPR biosensor exceeded the traditional biosensor detection limit. Accordingly, the SLG-SPR biosensor based on dynamic optical enhancement can realize high sensitivity detection of low concentration biomarkers and can be applied to most of the trace biomarkers in theory.

A new method of SPR signal amplification based on dynamic field enhancement at the sensor surface to detect C-reactive protein (CRP) is proposed. The gold nanoparticles-detection antibody (AuNPs-dAb) conjugates, as the dynamical agent, were applied to enhance the biosensor sensitivity. The mechanism of SPR sensitivity enhancement is due to the strong evanescent field coupling between the localized SPR (LSPR) of AuNPs and SPR of gold-silver alloy film which proved by COMSOL Multiphysics and MATLAB simulation. The biosensor sensitivity got with sandwich immunoassay (cAb/CRP/AuNPs-dAb) is 5.56-fold of the structure without AuNPs (cAb/CRP/dAb). Moreover, concentration of AuAg-SPR biosensor in CRP detection was lower for an order of magnitude than that of the conventional gold film cladding SPR (Au-SPR) biosensor, according to its direct reaction with the immobilized cAb. The dynamic field enhancement based AuAg-SPR biosensors have high sensitivity in detecting trace biomarker of CRP, and the improvement can also be applied to the detection of other biomarkers in low concentration sensitively.

Micro-hyperspectral imaging (MHSI) is an advanced sensor technology that exploits the distinct spectral signatures of samples for characterization, analysis, and identification. However, applying MHSI to the studies of materials at micro- and nano-scale remains constrained. Perovskite, an innovative material, has attracted widespread attention due to its exceptional optical properties, and the characterizing utilization of MHSI on micro- and nano-scale perovskite crystals represents a novel perspective for further comprehensive analysis of the optical characteristics of perovskite. In this study, we developed a home-built MHSI sensor system through the integration of a hyperspectral imaging sensor and a metallurgical micro-scope, enabling the acquisition of three-dimensional data of the micro-scale perovskite crystals (MAPbBr ₃ ) samples, which including the characterization imaging of the morphological structure of the samples and its high-resolution spectral response values for hundreds of spectral bands. Auxiliary verification methodologies, including white light interference, energy dispersive spectroscopy, and COMSOL simulation, were employed for the cross-analysis of complex interrelationships among compositional ratios, thickness, morphology, and optical properties in perovskite crystals (MAPbBr ₃ ), and to substantiate the data acquired by MHSI. Specifically, the relationship between thickness and elemental ratios of the crystal has been investigated to explain the optical properties of the ’fishbone’ sample, and morphology features have been studied to verify the optical properties of the ’pyramid’ sample. The strong correlation between the experimental results and auxiliary verification highlights the immense potential of MHSI sensor technology for the characterization and extensive in-depth optical analysis of micro-nano materials.