Department of Chemistry, Vivekananda College, Tiruvedagam West, Madurai-625 214, Tamilnadu, India.
Langmuir. 2012 Oct 9;28(40):14357-63. doi: 10.1021/la303136v. Epub 2012 Sep 25.
Optically tuned silver nanoparticles (AgNP's) functionalized with ω-mercaptoalkanoic acids are synthesized and used as a signal amplifier for the surface-enhanced resonance Raman scattering (SERRS) study of heme cofactor in methemoglobin (metHb). Even though both mercaptopropionic acid (MPA)- and mercaptononanoic acid (MNA)-functionalized AgNP's exemplify vastly enhanced SERRS signal of metHb, MNA-AgNP's amplify the SERRS signal amid preservation of the nativity of the heme pocket, unlike MPA-AgNP's. The electrostatic interaction between MNA-AgNP's and metHb leads to instant signal enhancement with a Raman enhancement factor (EF(SERS)) of 4.2 × 10(3). Additionally, a Langmuir adsorption isotherm has been employed for the adsorption of metHb on the MNA-AgNP surface, which provides the real surface coverage and equilibrium constant (K) of metHb as 139 nM and 3.6 × 10(8) M(-1), respectively. The lowest detection limit of 10 nM for metHb has been demonstrated using MNA-AgNP's besides retaining the nativity of the heme pocket.
用 ω-巯基链烷酸功能化的光学调谐银纳米粒子（AgNP's）被合成，并用作血红素辅基在高铁血红蛋白（metHb）中表面增强共振拉曼散射（SERRS）研究的信号放大器。尽管巯基丙酸（MPA）和巯基壬酸（MNA）功能化的 AgNP's 都表现出对 metHb 的 SERRS 信号的极大增强，但与 MPA-AgNP's 不同的是，MNA-AgNP's 在保持血红素口袋的天然状态的同时放大了 SERRS 信号。MNA-AgNP's 和 metHb 之间的静电相互作用导致信号即时增强，拉曼增强因子（EF(SERS)）为 4.2×10(3)。此外，还采用了 Langmuir 吸附等温线来研究 metHb 在 MNA-AgNP 表面的吸附，这提供了 metHb 的真实表面覆盖率和平衡常数（K）分别为 139 nM 和 3.6×10(8) M(-1)。使用 MNA-AgNP's 除了保留血红素口袋的天然状态外，还可以检测到最低 10 nM 的 metHb。
