Application of a magnetic biosensor based on novel cracker-shaped noble metal nanoparticles in dual-modal multidimensional detection of bladder cancer urinary biomarker HAase.

Herein, a novel noble-metal nanomaterial in the shape of a cracker (AuAgPt NTCs) was synthesized. The nanoparticles exhibit outstanding Surface-enhanced Raman spectroscopy (SERS) performance (enhancement factor: 1.09 × 107) due to the tip effect of the triangular structure and edge protrusion, and plasmonic coupling from its surface pores. Based on the excellent optical properties of AuAgPt NTCs and the dissociation of nanoparticles from magnetic beads induced by hyaluronidase (HAase) hydrolysis, a dual-mode biosensor for HAase detection was developed. In SERS mode, a tungsten disulfide film was used as the SERS substrate, enhancing the biosensor's SERS performance by approximately 45.6 ± 2.3% via chemical enhancement. SERS detection of HAase activity was achieved over the range 0.001 to 100 U·mL-1, with a limit of detection (LOD) of 0.0001 U·mL-1. In colorimetric mode, the protrusions on the edges and surface pores of the AuAgPt NTCs increase the effective interaction area between light and the nanoparticles, enhancing the extinction capacity of individual particles. Therefore, this biosensor achieves detection performance comparable to that of chemical catalytic methods without the use of chemical reagents. HAase activity was detected within the range of 10 to 100 U·mL-1, with an LOD of 3.9 U·mL-1. This greatly simplifies the workflow. Furthermore, an image analysis software (Bladder Guardian) was designed for rapid tiered screening of HAase activity, achieving an accuracy rate of 93.8 ± 2.6%. In summary, this study provides a novel tool for multidimensional detection of BC urinary biomarker HAase activity.