Fabrication of Miniature Surface Plasmon Resonance Sensor Chips by Using Confined Sessile Drop Technique

Abstract

In this study, we demonstrate a simple and efficient method to fabricate miniature surface plasmon resonance (SPR) sensor chips by using confined sessile drop technique. A liquid optical adhesive (NOA 61) was dropped on the circular flat surface of cylindrical substrates made of poly(dimethylsiloxane) (PDMS). The formation of hemispherical optical prisms was accomplished by taking advantage of the sharp edges of cylindrical PDMS substrates that prevented the overflow of liquid NOA 61 at the edge of substrates. The size of the hemispherical optical prisms can be controlled by changing the diameter of the cylindrical PDMS substrates. After UV curing, the SPR sensor chips were obtained by the deposition of 3 nm thick chromium and 47 nm thick gold on the flat side of the prisms. The fabricated miniature SPR sensor chips were then mounted on a three-dimensional-printed flow cell to complete the microfluidic SPR sensor module. The miniature SPR sensor chips provided a comparable sensitivity to the conventional high-refractive-index glass SPR chips. To demonstrate the detection capability of nanometer-sized materials, we applied the miniature microfluidic SPR system for monitoring the deposition of layer-by-layer ultrathin films of poly(diallyldimethylammonium chloride)/poly(sodium 4styrenesulfonate) and for detecting human immunoglobulin G.

BIO bragg gratings on microfibers for label-free biosensing

“…The implementation of some optical phenomena for biosensing such as SPR (Nootchanat et al, 2019;Zhao et al, 2019), SERS (Langer et al, 2020;Liu et al, 2020), and light interference (Chen et al, 2019;J. Wang et al, 2020) became the seed of a high scientific activity in the last decades, which have provided a great knowledge on innovative, sensitive and label-free bioanalytical systems.…”

Nanoplasmonic sensors for extracellular vesicles and bacterial membrane vesicles

“…In order to achieve the full potential of SPR-based detection for advanced healthcare, there is a need to miniaturize the bulky instruments required for the coupling of light with propagating SPPs and spectrometers [92]. Also, it is encouraging to achieve advancements in nanofabrication and innovative manufacturing methods, including flexible substrates, 3D printing, and fiber optics for making SPR-based sensors [93][94][95].…”

Optical Technologies for Single-Cell Analysis on Microchips

“…Grating-coupled SPR was established by combining a nanostructured gold grating with an SPR excitation and detection system, which could be further integrated in a PDMS microfluidic chamber for real-time monitoring of cell adhesion capability and cell-surface interaction with integral cell structures during the operational process. Nootchanat et al [80] fabricated a miniature SPR sensor chip via the confined sessile drop method (Figure 7B). By monitoring the deposition of layer-by-layer ultrathin films of poly(diallyldimethylammonium chloride)/poly(sodium 4-styrenesulfonate), the human immunoglobulin G could be detected with a higher sensitivity compared to common high-refractive-index glass SPR chips.…”