Zeng Binbin, Zong Xia, Dai Xinjue, Pan Lian, Cao Xiaowei, Lu Changhua
Jiangsu Key Laboratory of Integrated Traditional Chinese and Western Medicine for Prevention and Treatment of Senile Diseases, Medical College, Institute of Translational Medicine, Yangzhou University, Yangzhou, China.
Ophthalmology, The Affiliated Yixing Traditional Chinese Medicine Hospital of Yangzhou University, Wuxi, China.
Front Bioeng Biotechnol. 2025 Jul 18;13:1623332. doi: 10.3389/fbioe.2025.1623332. eCollection 2025.
Early detection and intervention in diabetic retinopathy (DR) are key to its prevention and treatment. In this study, we propose a surface-enhanced Raman scattering (SERS) bifunctional detection platform based on nanoenzymes catalyzing the tetramethylbenzidine (TMB) reaction, which innovatively introduces an aptamer recognition competition strategy and achieves an ultrasensitive detection of DR associated biomarker (VEGF). The platform employs Au@Pd nanorods (Au@Pd NRs) modified with single-stranded DNA1 (ssDNA1) as nanoenzymatic probes. Arrays of Au trioctahedra (Au TOHs) with surface-modified double-stranded structures, including aptamer strands and single-stranded DNA2 (ssDNA2), were used as capture substrates. When the target protein is present in the solution to be tested, the aptamer specifically recognizes the target protein and detaches from the surface of the capture substrate, exposing ssDNA2 and being recognized and bound by ssDNA1, allowing a large number of nanoenzymatic probes to be bound to the capture substrate, and the assay platform thus possesses excellent POD activity and SERS performance, being able to catalyze the generation of TMB with a strong SERS signal oxTMB. The platform demonstrated high detection performance, completing the assay within 14 min, with a low limit of detection (LOD) of 0.11 pg/mL. It maintained robust clinical performance even in complex serum samples, and the results were consistent with ELISA. This work offers a framework for constructing nanoenzyme-SERS bifunctional detection systems and introduces a new approach for biomarker detection.
糖尿病视网膜病变（DR）的早期检测和干预是其预防和治疗的关键。在本研究中，我们提出了一种基于纳米酶催化四甲基联苯胺（TMB）反应的表面增强拉曼散射（SERS）双功能检测平台，该平台创新性地引入了适体识别竞争策略，实现了对DR相关生物标志物（VEGF）的超灵敏检测。该平台采用用单链DNA1（ssDNA1）修饰的金@钯纳米棒（Au@Pd NRs）作为纳米酶探针。表面修饰有包括适体链和单链DNA2（ssDNA2）在内的双链结构的金三八面体（Au TOHs）阵列用作捕获底物。当目标蛋白存在于待测溶液中时，适体特异性识别目标蛋白并从捕获底物表面脱离，使ssDNA2暴露并被ssDNA1识别和结合，从而使大量纳米酶探针与捕获底物结合，进而该检测平台具有优异的过氧化物酶（POD）活性和SERS性能，能够催化产生具有强SERS信号的氧化型TMB（oxTMB）。该平台展现出高检测性能，在14分钟内完成检测，检测限低至0.11 pg/mL。即使在复杂的血清样本中，它也保持了强大的临床性能，且结果与酶联免疫吸附测定（ELISA）一致。这项工作为构建纳米酶-SERS双功能检测系统提供了框架，并引入了一种生物标志物检测的新方法。
