Xiao-yi Lü

Spectrometer-free biological detection method using porous silicon microcavity devices

This paper proposes a label-free and spectrometer-free method for biological detection with high detecting resolution. Taking advantage of the optical properties of porous silicon microcavity, the refractive index changes caused by biological reaction can be detected by measuring the incident angle of the minimum reflected light intensity. Based on the above method, label-free eight-base pair DNA detection can be realized with a corresponding detection limit is as low as 87 nM. This method provides high detecting resolution at a low equipment cost, and can be further used to develop an advanced instrument for biological detection.

Influence of electrolyte temperature onspectral properties of porous silicon microcavity

A porous silicon microcavity (PSM) is highly sensitive for sensing applications due to its high surface area and a narrow resonance peak. In this letter, we fabricated the PSM by alternate current density from a low value to a high value during double-tank electrochemical anodization at different electrolyte temperatures. Results show that with the increase of the electrolyte temperature, the rate of the PS etching becomes faster and the refractive index of the PS layer becomes smaller. The thickness of the PS increases faster than the decrease of the refractive index of the PS.