Based on the coordination principle of Lewis acids, a 4-mercaptophenylboronic acid (4-MPBA)-modified novel dumbbell-shaped Au–Ag nanorod (4-MPBA@DS Au–AgNR) substrate was developed, which could be combined with the surface-enhanced Raman scattering (SERS) technique to detect SO₄²⁻ with high sensitivity and specificity. DS Au–AgNRs synthesized in this study with a dumbbell-shaped structure were verified by finite-difference time domain (FDTD) simulation to be capable of stimulating strong localized electromagnetic enhancement (EM) at nano-edge and gap, generating a large number of “hot spots” exhibiting excellent SERS performance. The 4-MPBA modified on its surface could specifically recognize SO₄²⁻, producing a change in the spectral peak at 1382 cm⁻¹, thus realizing highly sensitive and specific sensing of SO₄²⁻. Under optimized conditions, this SERS sensor responded rapidly to SO₄²⁻ within 2 minutes and demonstrated outstanding specificity. Calculation of the ratio of the characteristic peaks at 1382 and 1070 cm⁻¹ (I₁₃₈₂/I₁₀₇₀) enabled the quantitative detection of SO₄²⁻ in the range of 1 × 10⁻⁸–1 × 10⁻³ M, and the detection threshold was as low as 1 nM, which was superior to those of similar detection methods. Importantly, the utility and reliability of this SERS substrate for the determination of SO₄²⁻ in actual samples were evaluated using ion chromatography as the gold standard, and there was no significant difference between the two protocols (P > 0.05), and the RSD was less than 6% with a satisfactory recovery rate (97.6–102.3%). Therefore, the present protocol has the advantages of simplicity and rapidity, high sensitivity, specificity, stability, and practicability in the determination of SO₄²⁻ in aqueous solution, providing a reliable solution for tracing SO₄²⁻ in the fields of food safety and environmental testing.

中文翻译：

---

基于苯硼酸修饰的新型哑铃形金银纳米棒SERS基底用于超灵敏检测SO42−

基于路易斯酸的配位原理，开发了一种4-巯基苯硼酸（4-MPBA）修饰的新型哑铃形Au-Ag纳米棒（4-MPBA@DS Au-AgNR）基底，该基底可以与表面结合-增强拉曼散射（SERS）技术以高灵敏度和特异性检测SO ₄ ²⁻ 。本研究合成的具有哑铃形结构的 DS Au-AgNRs 通过时域有限差分 (FDTD) 模拟验证能够在纳米边缘和间隙处激发强局域电磁增强 (EM)，产生大量的“热点”表现出出色的SERS性能。其表面修饰的4-MPBA可以特异性识别SO ₄ ^{2− ，使1382 cm -1}处的光谱峰发生变化，从而实现对SO ₄ ²⁻的高灵敏、特异性传感。在优化条件下，该 SERS 传感器在 2 分钟内对 SO ₄ ²⁻快速响应，并表现出出色的特异性。通过计算1382和1070 cm ^-1处的特征峰之比（I ₁₃₈₂ / I ₁₀₇₀），可以定量检测1 × 10 ^-8 –1 × 10 ^-3 M范围内的SO ₄ ²⁻，检测阈值低至1 nM，优于同类检测方法。重要的是，使用离子色谱作为金标准评估了该SERS底物测定实际样品中SO ₄ ²⁻的实用性和可靠性，两种方案之间没有显着差异（P > 0.05），并且RSD低于 6%，回收率令人满意（97.6–102.3%）。因此，本方法测定水溶液中SO 4 ₂₋^具有简单快速、灵敏度高、专属性强、稳定性强、实用性强的优点，为食品安全领域中SO ₄ ²⁻的追踪提供了可靠的解决方案。和环境测试。