Color blindness, or color vision deficiency (CVD), is an ocular disease that suppresses the recognition of different colors. Recently, tinted glasses and lenses have been studied as hopeful devices for color blindness correction. In this study, 2D biocompatible and flexible plasmonic contact lenses were fabricated using polydimethylsiloxane (PDMS) and a low-cost, and simple design based on the soft nano-lithography method and investigated for correction of red–green (deuteranomaly) color blindness. In addition, the stability test of the fabricated plasmonic contact lenses was investigated into the phosphate buffered saline (PBS) solution and the proposed lens offers an excellent stability into the PBS solution. The plasmonic contact lens proposed herein is based on the plasmonic surface lattice resonance (SLR) phenomenon and offers a good color filter for color blindness correction. The biocompatibility, low cost, stability, and simple fabrication of these contact lenses can offer new insights for applications of color blindness correction.

Combining biosensors with nanoscience provides great advantages such as being label-free and real time, highly sensitive, and small in size, as well as providing a low limit of detection and integration to other systems. That is why plasmonics finds various applications in drug detection, food safety, agriculture, photothermal therapy, etc. In this paper, we have fabricated a two-dimensional plasmonic grating biosensor using a soft lithography technique, which has eliminated some disadvantages of conventional plasmonic structures like expensive fabrication cost, inflexibility, and lack of mass production. On the other hand, we benefited from infrared neural stimulation for regulating membrane depolarization, which was based on photothermal mechanism and provided a contact-free and high spatial/temporal resolution. Eventually, the membrane depolarization of two different cell types of Hep G2 and mesenchymal stem cells cultured on two-dimensional plasmonic structure has been investigated under infrared neural stimulation. After preparing the soft plasmonic crystal, its reflection spectra and respective ellipsometry parameters were analyzed before and after cell culture with/without stimulation (near-infrared immune region ∼1450 nm). By comparing the obtained ellipsometry results for HEP G2 and mesenchymal stem cells, it is observed that the behavior of two cell types with respect to IR stimulation was the same as well as providing us the possibility of distinguishing the level of membrane depolarization under various stimulating frequencies. The strength of this integrated system for membrane depolarization detection has been shown experimentally, which can open new avenues toward neuroplasmonic application in the future.

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A novel 2D active plasmonic grating based on liquid crystal (LC) infiltration is demonstrated and theoretically analyzed, by combining the plasmonic properties of the gold nanostructure and the optical properties of the liquid crystal. In this structure, a thin layer of E7 liquid crystal was typically injected onto a gold nanostructure, deposited on a polydimethyl siloxane substrate, using nanoimprint lithography method. The surface plasmon resonance of the fabricated plasmonic structure can be controlled by changing the refractive index of the LC, which was achieved with an external electric field. LC molecules confined between the gold nanostructure and an indium–tin–oxide glass are randomly aligned, and they can exhibit a reversible refractive index, depending on their orientation under the external voltage and the polarization of the incident light. Both theoretical and experimental results demonstrate that the wavelength of the resonance peak can be red shifted by the electric field-dependent refractive index of the LC. This experimental work provides us an active control of surface plasmon resonance using LC which can act as an ideal active medium for different applications such as a low voltage sensor with a sensitivity of 0.4375 nm V−1.

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