Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun, 130012, China.
State Key Laboratory of Medicinal Chemical Biology, Tianjin Key Laboratory of Biosensing and Molecular Recognition, College of Chemistry, Nankai University, Tianjin, 300071, China.
Mikrochim Acta. 2018 Nov 10;185(12):540. doi: 10.1007/s00604-018-3039-4.
A ratiometric fluorescence method is described for the determination of the anticancer drug 6-mercaptopurine (6-MP). The method is based on the use of fluorescent MoS quantum dots (MQDs) and of the enzyme horseradish peroxidase (HRP). In the absence of 6-MP, HRP catalyzes the oxidation of o-phenylenediamine (OPD) by HO to form 2,3-diaminophenazine (DAP). This leads to quenching of the violet fluorescence of MQDs (measured at excitation/emission wavelengths of 360/415 nm), while the strong yellow fluorescence of DAP (peaking at 560 nm) becomes increasingly strong. In the presence of 6-MP, however, it will be preferentially oxidized by the HRP/HO system to form a disulfide dimer. Hence, less HO is available for the oxidation of OPD and less DAP will be formed. This results in the recovery of the violet fluorescence and a decrease of the yellow fluorescence. The ratio of the two signals can be used to quantify either HO or 6-MP. Linear responses are observed for HO in 0.5-140 μM concentration range, and for 6-MP in the 0.5-70 μM concentration range, with detection limits of 0.1 μM and 0.29 μM, respectively. The method was applied to the determination of 6-MP in spiked human urine and gave satisfactory results. Graphical Abstract Schematic of an enzymatic fluorometric method for determination of 6-mercaptopurine (6-MP). It is based on the presence of 6-MP that can inhibit the HRP-catalyzed oxidation of o-phenylenediamine (OPD) to form 2,3-diaminophenazine (DAP). Hence, the fluorescence resonance energy transfer (FRET) between DAP and MoS quantum dots (MQDs) is suppressed.
一种比率荧光法用于测定抗癌药物 6-巯基嘌呤（6-MP）。该方法基于使用荧光 MoS 量子点（MQDs）和辣根过氧化物酶（HRP）。在没有 6-MP 的情况下，HRP 催化 HO 对邻苯二胺（OPD）的氧化，形成 2,3-二氨基吩嗪（DAP）。这导致 MQDs 的紫色荧光猝灭（在 360/415nm 的激发/发射波长下测量），而 DAP 的强黄色荧光（在 560nm 处达到峰值）变得越来越强。然而，在存在 6-MP 的情况下，它将被 HRP/HO 系统优先氧化形成二硫键二聚体。因此，用于 OPD 氧化的 HO 减少，形成的 DAP 减少。这导致紫色荧光恢复，黄色荧光减少。两个信号的比值可用于定量测定 HO 或 6-MP。在 0.5-140μM 的浓度范围内，HO 呈现线性响应，在 0.5-70μM 的浓度范围内，6-MP 呈现线性响应，检测限分别为 0.1μM 和 0.29μM。该方法用于测定加标人尿中的 6-MP，结果令人满意。 图摘要 用于测定 6-巯基嘌呤（6-MP）的酶荧光法示意图。它基于存在 6-MP，其可以抑制 HRP 催化的邻苯二胺（OPD）氧化形成 2,3-二氨基吩嗪（DAP）。因此，DAP 和 MoS 量子点（MQDs）之间的荧光共振能量转移（FRET）受到抑制。
