D-penicillamine (D-PA) plays an important role in medical and clinical treatment of some diseases. In this work, we designed a sensitive fluorometric and colorimetric dual-mode assay on the basis of fluorescent silicon quantum dots (SiQDs) and 5,5-dithiobis-(2-nitrobenzoic acid) (DTNB) to effectively detect D-PA. The sulfydryl group (-SH) of D-PA can react with DTNB to generate 5-thio-2-nitrobenzoate (TNB), which has a broad absorption peak centered at 407 nm and is capable to absorb excitation light of SiQDs and greatly quench the fluorescence of SiQDs on account of inner filter effect (IFE). Meanwhile, the colour of the detection system obviously turned yellow. Consequently, the quantitative determination of D-PA can be achieved through both fluorometric and colorimetric methods. The fluorometric and colorimetric sensing platform can detect D-PA in 1-20 μM and 2-20 μM concentration range, respectively, and the limits of detection (LOD) were 0.48 μM and 0.68 μM, accordingly. Furthermore, the designed sensing platform was utilized to detect D-PA in real biological samples and the experimental results were satisfactory, suggesting the feasibility and potential applications of the sensing platform.

D-青霉胺（D-PA）在某些疾病的医学和临床治疗中起着重要作用。在这项工作中，我们基于荧光硅量子点（SiQDs）和5,5-二硫代双-（2-硝基苯甲酸）（DTNB）设计了一种灵敏的荧光和比色双模测定法，以有效检测D-PA。D-PA的巯基（-SH）可以与DTNB反应生成5-硫-2-硝基苯甲酸酯（TNB），其吸收峰集中在407 nm处，能够吸收SiQD的激发光并极大地猝灭由于内部过滤效应（IFE），SiQD的荧光。同时，检测系统的颜色明显变为黄色。因此，可以通过荧光法和比色法实现D-PA的定量测定。荧光和比色传感平台可以分别检测1-20μM和2-20μM浓度范围内的D-PA，因此检测限（LOD）分别为0.48μM和0.68μM。此外，所设计的传感平台被用于检测真实生物样品中的D-PA，实验结果令人满意，表明该传感平台的可行性和潜在的应用前景。