Detection of Haptoglobin by Surface-Enhanced Raman Scattering Based on the Shift of Characteristic Peak

Acute cerebral infarction (ACI) has the characteristics of onset nasty and high mortality, and thus the rapid determination of the occurrence and development of ACI plays a key role in the diagnosis, treatment and prognosis of ACI patients. It has shown that the serum level of human haptoglobin (Hp) is related to ACI. In this study, surface enhanced Raman scattering (SERS) combined with immune recognition was applied to establish a quantitative analysis method for serum Hp. Firstly, the SERS substrate of silver nanoparticles was prepared on silicon wafer, and 4-mercaptobenzoic Acid (MBA) was used as a Raman probe by forming Ag-S bond and connecting it on the surface of nanoparticles. The carboxyl group of MBA was linked to amino group of self-made high -affinity antibody through forming CO -NH structure thus forming a SERS self -assembled chip of Hp (Ag/ MBA/anti-Hp). Hp in serum could be specifically captured by antibodies on SERS substrate, which caused the shift of SERS characteristic peak of MBA. The results showed that there was a good linear relationship between the logarithm of Hp concentration and the SERS characteristic peak shift of MBA. The detection range was 1-1000 ng/mL (R2=0.988). The Hp concentrations in serum of 90 ACI patients were determined by this method, and the results were consistent with those of ELISA method, which proved the practicability and accuracy of this method. This method was highly specific, simple and convenient, which could realize the specific recognition and quantitative analysis of serum Hp, so as to be an effective means for clinical detection of serum Hp, thus providing a reference for the treatment and prognosis of ACI.