Sensitivity and detection limit analysis of silicon nanowire bio(chemical) sensors

This paper presents an analysis of the sensitivity and detection limit of silicon nanowire biosensors using an analytical model in combination with I-V and current noise measurements. The analysis shows that the limit of detection (LOD) and signal to noise ratio (SNR) can be optimized by determining an operating point in the depletion region with a large sensor transconductance, while maintaining a small system output noise amplitude. Both sensor and measurement configurations play equally important roles for optimal sensor performance. The analysis also shows that the LOD and SNR are minimally affected by the sensor cross-sectional geometry and size.