Advanced integrative construction of two-dimensional boron/phosphorus co-doped reticular mesoporous MXene frameworks for enhanced electrochemical guanine sensing application in serum

Ti3C2Tx MXene is renowned for its remarkable sensitivity in electrochemical sensing application but is prone to restacking. Herein, an advanced integrative construction method is introduced for synthesizing two-dimensional (2D) boron/phosphorus co-doped reticular mesoporous MXene frameworks (denoted as BPMMX). This strategy leverage Ti3C2Tx MXene as a precursor, zeolitic imidazolate frameworks (ZIF-67) nanocrystals as sacrificial templates, and boron phosphide as the dual source of boron and phosphorus. The resulting BPMMX structures effectively mitigate the restacking tendency of Ti3C2Tx MXene, enhancing the interlayer spacing and increasing the effective active surface area of the MXene nanomaterial. These structural enhancements facilitate faster electron transfer rates and provide additional active sites, significantly improving the overall performance of the Ti3C2Tx MXene nanomaterial. On this basis, a galvanic sensor for the determination of guanine (GU) was engineered by immobilizing of the BPMMX nanomaterial on electrode. The optimized sensor demonstrate a linear detection range spanning from 9.43 nM to 0.117 mM for GU, with a detection limit of 6.4 nM (S/N = 3). This study not only highlight the potential of MXene-based sensors for the quantitative analysis of GU but also pave the way for developing advanced materials with improved electrochemical sensing properties.