Miao Jiayi, Liu Yifan, Xiao Yi, Yuan Congzheng, Xu Qian, Chen Panpan, Jin Yang, Zhang Liying, He Hongliang, Du Shuhu
School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu, 211166, China.
School of Pharmacy, Nanjing Medical University, Nanjing, Jiangsu, 211166, China.
Biosens Bioelectron. 2025 Jul 15;280:117462. doi: 10.1016/j.bios.2025.117462. Epub 2025 Apr 8.
Perovskite/metallic heterojunction-based surface enhanced Raman scattering (SERS) substrates have been proven to be capable of providing Raman enhancement. However, the inherent water instability and poor dispersibility of perovskite/metallic nanocomposites-based SERS substrates pose significant challenges to their application in aqueous environments. Herein, polydopamine (PDA)-encapsulated cesium lead bromide (CsPbBr) adsorbing gold nanoparticles (AuNPs), termed as CsPbBr@PDA@AuNPs, is prepared as SERS substrate, which exhibits excellent water stability and SERS activity. Dopamine as organic ligand not only passivates surface defects during the growth of perovskite nanocrystals, but also forms porous PDA protective layer, effectively preventing degradation of perovskite in aqueous medium. Meanwhile, PDA with abundant functional groups and conjugated π structure will adsorb AuNPs and promote electron flow between CsPbBr and AuNPs, resulting in strong SERS activity. Based on the results, a SERS aptasensor has been fabricated by conjugation between CsPbBr@PDA@AuNPs and double-stranded DNA (dsDNA), which is composed of neuron-specific enolase (NSE) aptamer and partial complementary signal-stranded DNA (ssDNA). The working strategy of as-fabricated SERS aptasensor is based on the conformational change (of ssDNA)-triggered Raman response for the detection of NSE. Upon the addition of NSE, the specific binding of NSE aptamers to NSE can convert rigid dsDNA into a flexible ssDNA, and the Cy5 signal molecule modified at the end of ssDNA will close to CsPbBr@PDA@AuNPs SERS substrate, generating significant Raman signals with the lower limit of detection (1.02 pg/mL) of NSE. The SERS aptasensor has broad application prospect in the field of life/medicine science fields (e.g. early diagnosis and screening of disease).
基于钙钛矿/金属异质结的表面增强拉曼散射（SERS）基底已被证明能够提供拉曼增强。然而，基于钙钛矿/金属纳米复合材料的SERS基底固有的水不稳定性和较差的分散性对其在水性环境中的应用提出了重大挑战。在此，制备了一种吸附金纳米颗粒（AuNPs）的聚多巴胺（PDA）包裹的溴化铯铅（CsPbBr），即CsPbBr@PDA@AuNPs，作为SERS基底，其表现出优异的水稳定性和SERS活性。多巴胺作为有机配体不仅在钙钛矿纳米晶体生长过程中钝化表面缺陷，还形成多孔的PDA保护层，有效防止钙钛矿在水性介质中降解。同时，具有丰富官能团和共轭π结构的PDA会吸附AuNPs并促进CsPbBr与AuNPs之间的电子流动，从而产生强烈的SERS活性。基于这些结果，通过将CsPbBr@PDA@AuNPs与由神经元特异性烯醇化酶（NSE）适配体和部分互补的信号单链DNA（ssDNA）组成的双链DNA（dsDNA）共轭，制备了一种SERS适配体传感器。所制备的SERS适配体传感器的工作策略基于（ssDNA的）构象变化触发的拉曼响应来检测NSE。加入NSE后，NSE适配体与NSE的特异性结合可将刚性的dsDNA转化为柔性的ssDNA，并且在ssDNA末端修饰的Cy5信号分子会靠近CsPbBr@PDA@AuNPs SERS基底，产生显著的拉曼信号，NSE的检测下限为1.02 pg/mL。该SERS适配体传感器在生命/医学科学领域（如疾病的早期诊断和筛查）具有广阔的应用前景。
