Du Qingyu, Zhang Haoyu, Bi Yingna, Wang Huijie, Zhou Xuemin, Shi Pengfei, Lv Shuzhen, Bi Sai
College of Chemistry and Chemical Engineering, Key Laboratory of Shandong Provincial Universities for Functional Molecules and Materials, Qingdao University, Qingdao 266071, P. R. China.
Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, College of Medicine, Linyi University, Linyi 276000, P. R. China.
Anal Chem. 2025 Feb 25;97(7):4049-4056. doi: 10.1021/acs.analchem.4c05841. Epub 2025 Feb 13.
Near-infrared light (NIR)-driven photoelectrochemical (PEC) processes are mainly faced with the limitation of weak photocurrents. Here, N-deficient B-doped -CN/CdS (NB--CN/CdS) is proposed to construct a NIR-driven PEC biosensor assisted by CRISPR-Cas12a system for the determination of microRNA-21 (miRNA-21). To promote the optical absorption as well as the separation of photogenerated electrons and holes of -CN, NB--CN/CdS is constructed via engineering the electronic and band structure in terms of N defect, B doping, and heterojunction, achieving high PEC performance. To obtain the high luminescence efficiency for exciting NB--CN/CdS under NIR, the core-shell NaYF:Yb, Tm@NaYF upconversion nanoparticles (UCNPs) with repaired defects are prepared. Furthermore, the rolling circle amplification (RCA)-assisted CRISPR-Cas12a system is integrated to fragment the DNA on UCNPs, achieving sensitive detection of miRNA-21. On the one hand, the uncleavaged signal probes on UCNPs combined with NB--CN/CdS through π-π stacking interaction, generating photocurrents under the irradiation of NIR. On the other hand, the cleavaged signal probes which cannot link with NB--CN/CdS exhibited the fluorescence (FL) signals. The proposed PEC-FL dual-mode biosensor provides a mutual authentication of testing results and demonstrates ultrasensitivity (the detection limit of 1.1 fM for PEC mode and 7.0 fM for FL mode) and excellent specificity, which is promising in the clinical analysis of miRNA.
近红外光（NIR）驱动的光电化学（PEC）过程主要面临光电流较弱的限制。在此，提出了氮缺陷硼掺杂的 -CN/CdS（NB--CN/CdS），构建一种由CRISPR-Cas12a系统辅助的近红外光驱动的PEC生物传感器，用于检测微小RNA-21（miRNA-21）。为了促进 -CN的光吸收以及光生电子和空穴的分离，通过氮缺陷、硼掺杂和异质结来调控电子和能带结构，构建了NB--CN/CdS，实现了高PEC性能。为了在近红外光下获得激发NB--CN/CdS的高发光效率，制备了具有修复缺陷的核壳结构NaYF:Yb,Tm@NaYF上转换纳米颗粒（UCNPs）。此外，集成了滚环扩增（RCA）辅助的CRISPR-Cas12a系统，以切割UCNPs上的DNA，实现对miRNA-21的灵敏检测。一方面，UCNPs上未切割的信号探针通过π-π堆积相互作用与NB--CN/CdS结合，在近红外光照射下产生光电流。另一方面，不能与NB--CN/CdS连接的切割后的信号探针表现出荧光（FL）信号。所提出的PEC-FL双模式生物传感器提供了测试结果的相互验证，并展示了超灵敏性（PEC模式下的检测限为1.1 fM，FL模式下为7.0 fM）和优异的特异性，在miRNA的临床分析中具有广阔前景。
