Application Of Porous Silicon Optical Biosensor Based On Semiconductor Colloidal Quantum Dots Fluorescence

Porous silicon is a kind of one-dimensional photonic crystal with spongy structure,PSi after solution treatment,the low fluorescence background and infrared light,easy to prepare various photonic devices.With the combination of different mechanisms of fluorescence and PSi photonic devices,the sensitivity of biological detection is greatly improved,which can make the performance of PSi optical biosensor and biochip more excellent.In this paper,we combine the excellent optical properties of PSi with the good biological properties of quantum dots(QDs),a highly sensitive fluorescent optical biosensor was designed and fabricated,and effective biological detection was carried out.The following are the main contents and conclusions of this paper:1.Activation of carboxyl group of water-soluble CdSe/ZnS QDs by coupling agent N-(3-Dimethylaminopropyl)-N ?-ethylcarbodiimide hydrochloride(EDC)and N-Hydroxysulfosuccinimide sodium salt(Sulfo-NHS),the corresponding PSi photonic devices were designed according to the fluorescence peak of QDs,and QDs was successfully covalently linked with functionalized PSi with amino groups,which enhanced the fluorescence intensity of QDs in PSi.2.In order to verify the feasibility of porous silicon optical biosensor based on fluorescence of QDs,We added PBS?QD labeled biotin and biotin to streptavidin modified PSi,through the comparison of the fluorescence,the results showed that only QD labeled biotin was added to the streptavidin modified PSi to produce the fluorescence.It is proved that the feasibility of porous silicon optical biosensor based on QDs fluorescence,and then the detection of SA with different concentrations,the detection limit is 100 pM.3.In order to expand the application of porous silicon optical biosensor based on quantum dots fluorescence,the biosensor was used to detect the hydatid disease.First,the QD was labeled with the antibody of echinococcosis,and then reacted withdifferent concentrations of hydatid antigen modified PSi.The results showed that the concentration of hydatid antigen was linearly correlated with the intensity of QD immunoreactivity in PSi,and the detection limit was 500fg/ml.