Fabrication of cell recognition device by the luminescent nanocrystalline silicon and development of the biomedical measurement system

点击翻译按钮获取中文摘要

Luminescent semiconductor nanoparticles such as cadmium sulfide (CdS) and cadmium selenide (CdSe) have been widely studied for application to biomedical engineering fields. These nanoparticle materials, however, have some problems for safety to living organism, production cost, resource, environmental influence and particle size. Therefore, it is expected to develop the new nanoparticle materials with some features of unharmfulness, moderate price, resourcefulness, low environmental influence and minimal particle size. We have been fabricated the nanocrystalline silicon (nc-Si) particles, which continuously emits from red light up to blue light by controlling the particle size.In this study, the luminescent property and flow condition of nc-Si particles in the vein of animal have been investigated. The nc-Si particles with a size of 2.5 nm embedding in an oxidized layer were formed on a Si substrate by co-sputtering of Si chips/silica targets and post-annealing at high temperature. The … More oxidized layer surrounding nc-Si particles, then, was etched in hydrofluoric (HF) acid steam to effectively extract the many particles onto the substrate surface. After etching treatment, the sample was rinsed in the pure water, because the HF acid particle adsorbed on the surface of nc-Si particle have the high toxicity for the living organism. The nc-Si particles after rinse treatment were shaken off from the substrate into the normal saline solution (NSS) by supersonic vibration treatment. After that, the NSS containing the nc-Si particles was injected into the vein of animal such as rat and lamb. The luminescent property of nc-Si particles in the vein was easily detected by using a photonic multichannel analyzer. A Xenon lamp was used as the light source with an optical bandpass filter of 313 nm. When the nc-Si particles were injected at the particle concentration of 1.3 mg in the vein, they stably and smoothly flowed into their channels. Moreover, they exhibited strong red luminescence with a peak at 720 nm under the flow condition of nc-Si particles in the vein. The good flow and red luminescence was also confirmed for the various positions such as a coronary artery and wall of the small intestine in the living organism. These phenomenon were achieved by the formation of particle with the small size of 2.5 nm and existence of stable passivation film on the particle surface. Less