Abstract / Summary
Abstract Colitis is an inflammatory bowel disease with an incidence rate that has been rising year by year; however, there is currently a lack of simple and sensitive serological tests for its early diagnosis. This study developed a surface-enhanced Raman scattering (SERS) detection platform based on a magnetic core-shell composite structure (Fe 3 O 4 NRs@MPBA@β-lactose-Au NPs@PATP/MPBA). This platform utilized a target-induced enzymatic release process to trigger a light-coupled signal amplification reaction, thereby enabling the sensitive detection of senescence-associated β-galactosidase (SA-β-gal), a serum biomarker of colorectal inflammation. During the detection process, the target SA-β-gal specifically hydrolyzed the galactosidic bonds in β-lactose, causing the SERS probe to dissociate and be released from the surface of the capture probe. Subsequently, p-aminobenzenethiol (PATP) on the surface of SERS probes could undergo an in situ photocoupling reaction upon laser irradiation, converting to 4,4′-dithioazobenzene (DMAB), as evidenced by a significant decrease in the characteristic Raman signal at 1397 cm − 1 . The detection range of this SERS detection platform spanned 10 − 4 to 10 U/mL, with a limit of detection (LOD) as low as 1.956 × 10 − 6 U/mL. The platform showed good sensitivity and specificity in serum samples, and could effectively distinguish the difference of serum SA-β-gal levels between colitis model mice and healthy control mice. Compared with the colorimetric method, the detection results of actual serum samples had good accuracy. This study shows great promise for clinical application in the early serological screening of colorectal inflammation.