A porous organic polymer nanosphere-based fluorescent biosensing platform for simultaneous detection of multiplexed DNA via electrostatic attraction and π-π stacking interactions

One key challenge in oligonucleotide sequence sensing is to achieve multiplexed DNA detection in one sensor. Herein, a simple and efficient fluorescent biosensing platform is constructed to simultaneously detect multiplexed DNA depending on porous organic polymer (POP) nanospheres. The developed sensor is based on the concept that the POP nanospheres can efficiently quench the fluorescence emission of dye-labeled single-stranded DNA (ssDNA). Fluorescence quenching is achieved by the non-covalent assembly of multiple probes on the surface of POP nanospheres through electrostatic attraction and pi-pi stacking interactions, in which the electrostatic attraction plays a more critical role than pi-pi stacking. The formed dsDNA could be released off the surface of POP via hybridizing with the target DNA. Consequently, the target DNA can be quickly detected by fluorescence recovery. The biosensor could sensitively and specifically identify three target DNAs in the range of 0.1 to 36 nM, and the lowest detection limits are 50 pM, 100 pM, and 50 pM, respectively. It is noteworthy that the proposed platform is successfully applied to detect DNA in human serum. We perceive that the proposed sensing system represents a simple and sensitive strategy towards simultaneous and multiplexed assays for DNA monitoring and early clinical diagnosis.

Automated summary

A simple and efficient fluorescent biosensing platform based on porous organic polymer (POP) nanospheres was developed for simultaneous detection of multiplexed DNA. This platform utilizes electrostatic attraction and pi-pi stacking interactions to efficiently quench the fluorescence emission of dye-labeled single-stranded DNA (ssDNA), allowing for quick and sensitive detection of target DNA. The biosensor can sensitively and specifically identify three target DNAs with detection limits as low as 50 pM, and is successfully applied in detecting DNA in human serum for potential early clinical diagnosis.