Institute of Applied Mechanics, National Taiwan University, No.1, Sec. 4, Roosevelt Rd., Da'an Dist., Taipei City 106, Taiwan.
Research Center for Applied Sciences, Academia Sinica, 128 Academia Road, Section 2, Nankang, Taipei 115-29, Taiwan.
ACS Sens. 2022 Sep 23;7(9):2597-2605. doi: 10.1021/acssensors.2c00850. Epub 2022 Sep 12.
We present the use of surface charges in dual gold-nanoslit electrodes to improve the surface plasmon resonance (SPR) detection limit by several orders of magnitude. The SPR is directly generated by gold-nanoslit arrays in the two electrodes. The SPR shifts for both nanoslit arrays are measured simultaneously with a simple hyperspectral setup. When biomolecules are captured by specific antibodies on the dual electrodes, the surface charge is changed during the electrochemical process due to the increase in surface impedance. The push-pull-type electrodes generate opposite surface charges. Using the differences in both spectral shifts, the change in surface charge is detected sensitively. We demonstrate that using a [Fe(CN)] redox process after antigen-antibody interactions, the dual nanoslit electrodes show an enhancement of the detection limit from 1 μg/mL to 10 pg/mL.
我们提出利用双金纳米缝电极中的表面电荷来提高表面等离子体共振（SPR）的检测极限，提高了几个数量级。两个电极中的金纳米缝阵列直接产生 SPR。通过简单的高光谱设置同时测量两个纳米缝阵列的 SPR 位移。当生物分子被双电极上的特定抗体捕获时，由于表面阻抗的增加，在电化学过程中表面电荷发生变化。推挽式电极产生相反的表面电荷。利用两个光谱位移的差异，灵敏地检测到表面电荷的变化。我们证明，在抗原-抗体相互作用后使用[Fe(CN)]氧化还原过程，双纳米缝电极将检测限从 1μg/mL 提高到 10pg/mL。
