Chemiluminescent aptasensor for chloramphenicol based on N-(4-aminobutyl)-N-ethylisoluminol-functionalized flower-like gold nanostructures and magnetic nanoparticles.

A novel chemiluminescent aptasensor for the highly sensitive detection of chloramphenicol (CAP) in milk was successfully developed using biotinylated CAP aptamer-functionalized magnetic nanoparticles (MNPs) as capture probes and thiolated hybridized complementary strand-modified N-(4-aminobutyl)-N-ethylisoluminol (ABEI)-functionalized flower-like gold nanostructures (AuNFs) as signal probes. P-iodophenol (PIP) was also added to form an ABEI-H2O2-PIP steady-state chemiluminescence (CL) system. Based on a competitive format, the CL intensity was negatively correlated with the concentration of CAP in the range of 0.01-0.20 ng/mL and the detection limit was 0.01 ng/mL in buffer and 1 ng/mL in milk. The proposed method was successfully applied to measure CAP in milk samples and compared to a commercial ELISA method. The high sensitivity of AuNFs, excellent selectivity and stability of aptamers, and good overall stability of the chemiluminescent bioassay with magnetic separation make them a promising approach for the detection of small molecular illegal additives. Additionally, the high sensitivity, easy operation, and good reproducibility exhibited by the stable chemiluminescent bioassay demonstrate its applicability for the trace detection of CAP in applications, such as animal husbandry.