A novel near-infrared AP-M@AntiACLY detection probe based on SERS to trace detection of serum ACLY for early diagnosis of pediatric sepsis

Sepsis is a critical condition characterized by high morbidity and mortality. The development of technologies for early recognition of sepsis is essential for enhancing patient outcomes. Our original finding indicates that ATP-citrate lyase (ACLY) holds promise as a diagnostic biomarker for sepsis; however, sensitive methods for detecting trace levels of ACLY in serum are currently lacking. We have therefore developed a novel AP-M@Anti ACLY detection probe based on surface-enhanced Raman scattering (SERS) for the detection of serum ACLY. The AuNBPs@MBA was synthesized using gold nanobipyramids (AuNBPs) as the base and 4-mercaptobenzoic acid (4-MBA) as a reflective indicator for ACLY activity. Specifically, the Raman signal of 4-MBA decreases proportionally with an increase in ACLY concentration. ACLY antibodies were subsequently linked to AuNBPs@MBA via the gold-sulfur bonds and blocked with bovine serum albumin (BSA). Under optimized conditions, the probe exhibits a strong linear correlation between Raman signal and ACLY concentrations, ranging from 1 pg/mL - 0.5 ng/mL (R 2 = 0.998) and 0.1–500 ng/mL (R 2 = 0.999), with a remarkable limit of detection (LOD) of 1.0 pg/mL. AP-M@Anti ACLY detection probe surpasses enzyme-linked immunosorbent assay (ELISA) when testing septic children's serum samples in terms of its detection range, accuracy, and analysis time. Recovery rates ranged from 96.80 % to 102.52 %. In conclusion, all results suggest that AP-M@Anti ACLY detection probe is a promising tool for the early diagnosis of sepsis and offers new insights into the development of preclinical approaches.