Rapid aptasensor capable of simply detect tumor markers based on conjugated polyelectrolytes

In this paper, a very simple, easily-operated and universal platform is proposed for tumor marker detection. In this strategy, tumor marker-specific aptamer, which can quench the fluorescence of polyfluorene-based cationic conjugated polyelectrolytes (PFN⁺), are used as recognizing probes. Upon addition of tumor marker, the aptamer can be assembled into the tumor marker-aptamer complex, resulting in fluorescence recovery of PFN⁺ and the detection of the targets. The most widely-used tumor markers, carcinoembryonic antigen (CEA) and fetoprotein (AFP) have been chosen as the model analytes for this work. The sensing method is capable of rapidly detect target protein within 5 min without complex handling procedure and expensive instruments. Compared with previous studies, the assay presented here is really simple and avoids either conjugated polyelectrolytes (CPEs) modification or oligonucleotide labeling. This method also shows a wide detection range of 3 orders of magnitude and the detection limit is 0.316 ng/mL for CEA and 1.76 ng/mL for AFP. Furthermore, the approach requires only a convenient"mix-and-detect" procedure and offers a universal platform for the sensitive detection of any target molecule of choice according to the selected aptamer.