Pt/Ti3C2Tx nanozyme-amplified colorimetric lateral flow biosensor for dual-readout detection of HIV-DNA

Rapid and sensitive virus genes detection with point-of-care testing is the key to improving the probability of survival and lowering infectious rate. Here, we proposed a sensitive and quantitative colorimetric lateral flow biosensor (CLFB) for human immunodeficiency virus-DNA (HIV-DNA) detection with a novel nanomaterial (Pt nanoparticles decorated Ti3C2Tx MXene, Pt/Ti3C2Tx) as signal reporters. Pt/Ti3C2Tx was synthesized by a self-reduction method with Ti3C2Tx as both reducing agent and supporter. Each Pt/Ti3C2Tx contained hundreds of Pt nanoparticles to achieve enhanced colorimetric dual-readout, which can not only show gray color itself, but also catalyze its substrate to produce more obvious red color within 3 min. The integration of mimic enzyme property of Pt/Ti3C2Tx improved the colorimetric signal brightness and decreased naked-eye detection limit of HIV-DNA to 0.1 nM relative to original 0.8 nM. Capture DNA was further modified onto the Pt/Ti3C2Tx to realize specific binding with HIV-DNA, enabling the CLFB good reproducibility with an average intra-assay deviation of 4.3% and an inter-assay deviation of 4.2% respectively. Furthermore, the successful detection of HIV-DNA in serum samples demonstrated its great application potential in real samples and timely diagnosis.