Enhanced Biosensor Based on Assembled Porous SiliconMicrocavities Using CdSe/ZnS Quantum Dots

To further improve the sensitivity of porous siliconassembled microcavity biosensors, the detection of porous silicon assembled microcavity by angle spectrum method is also researched. This contribution uses CdSe/ZnS quantum dot-labelled probeDNAto amplify the refractive index and detect it by the angle spectrummethod. The first layer is amicrocavity layer, and the next is porous silicon with a Bragg structure. After functionalization, different concentrations of target DNA were coupled to construct quantum dot-labelled probe DNA to bind specifically to the target DNA. With the Bragg device based on quartz glass forming an assembled microcavity structure, using a He-Ne laser as the detection light and collimation beam, the angle spectrum method is used to detect different concentrations of target DNA before and after biological reaction with quantum dot-labelled probe DNA and reflect the angle of minimum light intensity. The experimental results show that with increasing target DNA concentration, probe DNA concentration and angle, the detection limit is 13.25 pM. The angle-spectrum method has been successfully used to detect the assembled porous silicon microcavity. The angle-spectrum method has the advantages of spectrometer free and low cost.

Automated summary

The angle spectrum method was used to further improve the sensitivity of porous silicon-assembled microcavity biosensors, successfully detecting different concentrations of target DNA with a detection limit of 13.25 pM. This method offers advantages such as being spectrometer free and cost-effective.