Determination of low solvent concentration by nano-porous silicon photonic sensors using volatile organic compound method

AbstractA vast majority of the organic solvents used in industry and laboratories are volatile, hazardous and toxic organic compounds, they are considered as a potent problem for human health and a cause of environmental pollution. Although analytical laboratory methods can determine extremely low solvent concentration, the sensing method with low cost and high sensitivity remains a conundrum. This paper presents and compares three methods (volatile organic compound (VOC), liquid drop and saturated vapour pressure) for determination of organic solvents in liquid environment by using photonic sensor based on nano-porous silicon (pSi) microcavity structures. Among those, the VOC method provides the highest sensitivity at low solvent volume concentrations because it can create a high vapour pressure of the analyte on the sensor surface owing to the capillary deposition of organic solvent into the silicon pores. This VOC method consists of three steps: heating the solution with its particular boiling temperat...