Centre for Nanotechnology, Indian Institute of Technology Guwahati, Assam, 781039, India.
Centre for Nanotechnology, Indian Institute of Technology Guwahati, Assam, 781039, India; Jyoti and Bhupat Mehta School of Health Sciences and Technology, Indian Institute of Technology Guwahati, Assam, 781039, India; Department of Electronics and Electrical Engineering, Indian Institute of Technology Guwahati, Assam, 781039, India.
Biosens Bioelectron. 2025 Jan 15;268:116885. doi: 10.1016/j.bios.2024.116885. Epub 2024 Oct 28.
We report the synthesis of bimetallic plasmonic nanostructure of silver shelled gold nanorods (Ag-Au NRs), subsequently employed for the selective detection of cholesterol (Cho) and triglycerides (TGl) utilizing Surface Enhanced Raman Spectroscopy (SERS). In this direction, the gold nanorods (Au NRs) were synthesized via seed mediated growth method followed by forming a silver shell with reduction of AgNO onto Au NRs. Ag-Au NRs showed significantly augmented SERS property owing to hybridization of Localized Surface Plasmon Resonances (LSPR) of silver and gold. The enhanced plasmonic property was thus employed for biosensing. For this, two different Raman reporter molecules, 5,5'-dithiobis-(2-nitrobenzoic acid) (DTNB) and 4-aminothiophenol (4ATP) were immobilized separately on Ag-Au NRs to synthesize SERS active nanoprobes, before the attachment of the bioreceptors - cholesterol oxidase (ChOx) and lipase (Lp) to form ChOx-DTNB-Ag-Au NRs and Lp-4ATP-Ag-Au NRs. These nanoprobes were then utilized for the quantification of Cho and TGl via liquid mode Raman spectroscopic study. The change in SERS spectral intensity of DTNB and 4ATP were systematically recorded in reference to the baseline sample to mark the calibration for both Cho and TGl. Additionally, interference studies considering effects of ascorbic acid, glucose, sodium and potassium ion were performed to unveil excellent selectivity of the proposed method.
我们报告了银壳金纳米棒（Ag-Au NRs）的双金属等离子体纳米结构的合成，随后利用表面增强拉曼光谱（SERS）用于胆固醇（Cho）和甘油三酯（TGl）的选择性检测。在这个方向上，通过种子介导的生长方法合成金纳米棒（Au NRs），然后通过将 AgNO 还原到 Au NRs 上来形成银壳。Ag-Au NRs 表现出显著增强的 SERS 特性，这是由于银和金的局域表面等离子体共振（LSPR）的杂交。增强的等离子体特性因此被用于生物传感。为此，将两种不同的拉曼报告分子，5,5'-二硫代双（2-硝基苯甲酸）（DTNB）和 4-氨基硫酚（4ATP）分别固定在 Ag-Au NRs 上以合成 SERS 活性纳米探针，然后将生物受体-胆固醇氧化酶（ChOx）和脂肪酶（Lp）连接到形成 ChOx-DTNB-Ag-Au NRs 和 Lp-4ATP-Ag-Au NRs。然后利用这些纳米探针通过液相拉曼光谱研究来定量检测 Cho 和 TGl。系统地记录了 DTNB 和 4ATP 的 SERS 光谱强度变化，以参考基线样品标记 Cho 和 TGl 的校准。此外，还进行了考虑抗坏血酸、葡萄糖、钠和钾离子影响的干扰研究，以揭示所提出方法的优异选择性。
