Novel fluorescent biosensor for carcinoembryonic antigen determination via atom transfer radical polymerization with a macroinitiator

In this paper, a high sensitivity and accuracy biosensor for CEA detection based on atom transfer radical polymerization (ATRP) with beta-cyclodextrin (beta-CD) and 2-bromoisobutyryl bromide (BIBB) as a macroinitiator is reported for the first time. Carcinoembryonic antigen (CEA), as a tumor-associated antigen, can be of great significance in the diagnosis of illness. Herein, thiolated CEA-aptamer 1 (Apt 1) at the 5 '-terminal is first immobilized on amino magnetic beads (MBs) via a cross-linking agent to specifically recognize the antigen of CEA. After the sandwich-type structure formed, beta-CD, with a bridging effect, is linked to the carboxylation CEA-aptamer 2* (Apt 2*) and BIBB via esterification reaction and substitution reaction, respectively. Remarkably, the combination of beta-CD and the initiators BIBB can provide a large number of active sites for monomers and significantly amplify the fluorescent signal. Under optimum experimental conditions, the proposed biosensor for detecting CEA has a strong linear relationship in the wide detection range of 1.0 x 10(-15)-1.0 x 10(-7) g mL(-1) (R-2 = 0.9989), and it is capable of detecting as low as 6.76 ag mL(-1) CEA. Furthermore, the fluorescence biosensor exhibits splendid analytical performance in practical sample analysis. More importantly, the excellent sensitivity with outstanding anti-interference properties of this proposed biosensor makes it of great potential in the field of bioanalytical applications.

Automated summary

The study introduces a biosensor for CEA detection using ATRP technology, which shows high sensitivity and accuracy. The biosensor has a unique structure and is capable of accurately detecting CEA concentrations in a wide range. It exhibits strong linear relationship, excellent analytical performance, and outstanding sensitivity with anti-interference properties in practical sample analysis.