A novel flexible magnetoelastic biosensor with “sandwich” structure based on transferrin encapsulated gold nanoclusters for 5-hydroxytryptamine detection

Abstract

5-hydroxytryptamine (5-HT), a mono-amine neurotransmitter, plays an important role in regulating the dynamics of neural circuits in the central nervous system and enteric nervous system. Accurate and sensitive monitoring of 5-HT will provide critical information for diagnosing many psychiatric and neurological disorders. However, there are no superior clinical assays for the detection of 5-HT, and existing methods of gas chromatographs and mass spectrometers are expensive, limiting portable and real-time monitoring as diagnostic approaches in the clinical setting. Therefore, a convenient, rapid, and low-cost method for the detection of 5-HT is still in demand in current clinical medicine. Herein, a novel flexible magnetoelastic (ME) biosensor with “sandwich” structure is proposed for 5-HT detection based on transferrin encapsulated gold nanoclusters (Tf-AuNCs). Combined with the magnetoelastic effect of CoFe2O4, the excellent conductivity of silver nanowires (AgNWs), and the fluorescence properties of Tf-AuNCs, the ME biosensor designed in this paper can achieve multi-signal recognition. Rapid and sensitive detection of 5-HT is achieved by a biosensing process that converts surface stress signal into magnetoelectric signals. The biosensor is capable of detecting 5-HT with different concentrations in a linear range of 10 ng/mL-100 μg/mL (R2 = 0.97119) with a lower detection limit (LOD) of 0.33 ng/mL. The accurate measurement results of 5-HT in human serum of clinical samples demonstrated the feasibility of the biosensor for 5-HT detection. This flexible ME biosensor was prepared in a simple process with great specificity and stability, providing a portable analytical device for the rapid and sensitive detection of 5-HT, which is of great significance for the clinical research of various neurological diseases.