The Biosensing Applications Of Silicon-based Nanomaterials And Cytotoxicity Assessment Of Silicon Nanowires

Silicon nanomaterials are a type of important semiconductor nanomaterials withattractive properties including excellent electronic/mechanical properties, favorablebiocompatibility, huge surface-to-volume ratios, surface tailorability, as well as theircompatibility with conventional silicon technology. Consequently, there has been greatinterest in developing functional silicon nanomaterials for various applications rangingfrom electronics to biology. So, in this paper we have mainly developed the surfaceenhanced Raman scattering (SERS) stroma based the silicon nanomatrials, which iscapable of specific、sensitive and multiplex detection of DNA；otherwise，we also havestudied the biological effect of the silicon nanowires in the cellular level as follows:1． In this communication, we present a kind of silicon-based SERS-active andreproducible substrate, i.e., silver nanoparticles decorated-silicon wafers (AgNPs@Si),which is capable of facile, sensitive, and multiplex detection of DNA. Significantly, theAgNPs@Si features excellent SERS reproducibility and high enhancement factor. Ourexperiment further demonstrates such resultant silicon-based SERS substrate isefficacious for multiplexed DNA detection with high sensitivity and specificity. Ourresearch has positive significance to develop the favorable reproducibility of SERSsubstrate and the detection of biomolecule based SERS.2．We have systematacially investigated the cytotoxicity of three kinds ofsilicon nanowires with different surface features to the tumor and normal cell linesunder the different conditions (e.g., the concentration and the incubation time and so on)by the classical biological methods, such as the MTT toxicity test、fluorescence imagingand the flow cytometry. Our studies show that the cytotoxicity of the silicon nanowireshave obvious dependence to the concentration and the incubation time: the cell activitydecrease obviously with the prolong of the incubation time and the increase of the concentration; the toxicity of the tumor cells is higher than the normal cells in the sameconditions; the surface property the silicon nanowires has the obvious impact tocytotoxicity. On that basis, we also have given the safety threshold velocity of thesilicon nanowires used in bioapplication of the cell level.