Construction And Applications Of New Biosensing Techniques

Biosensing technique has been widely used in medical diagnosis,environmental monitoring,food engineering and other fields.In the research field of biosensing,efficient bioimmobilization techniques and highly sensitive fluorescent probe are essential for development of biosensors.Bio-immobilization technique can be used to prepare recognition elements of biosensors.However,traditional bio-immobilization techniques generally suffer from poor stability,low efficiency or complicated operation,etc.It is very important to develop new bioimmobilization technique to solve these problems.Moreover,fluorescent sensing has received extensive attention due to its extremely high sensitivity and simple operation.However,traditional fluorophores suffer from the effect of aggregation caused quenching(ACQ),which may lead to high background signal and low sensitivity in practical applications.The emergence of fluorescent materials with aggregation-induced emission(AIE)features could well solve this problem.It is of great significance to develop new AIE probes for bioassay.Based on the above two aspects,this thesis develops a new bio-immobilization technique based on spontaneous amino-yne click reaction and a new AIE probe,and explored their application in biosensing.First,a novel activated ethynyl modified surface was designed and prepared using the spontaneous amino-yne click reaction.Chemical compounds and biomolecules can be immobilized on the activated ethynyl surface spontaneously and efficiently.Native proteins could be covalently immobilized on the surfaces in as short as 30 minutes and their biological activity is intact.Furthermore,we combined the amino-yne click reaction with microfluidic technology and microcontact printing technology(?CP)to seed proteins and cells on the surfaces with well-defined patterns,which is promising for application in tissue engineering.Notably,the activated ethynyl surfaces were proved to possess higher protein immobilization efficiency,better immobilization stability and lower background fluorescence than the commercial aldehyde surfaces,which demonstrated potentials for commercial application in biosensors and biochips.Second,a new turn-on AIE probe of TPE-Im for detecting thiol group containing proteins was designed and prepared based on restriction of intramolecular motion(RIM)and photoinduced electron transfer(PET).Bovine serum protein and human albumin could be detected quickly and quantitatively by TPE-Im in a large concentration range(10 ?g / m L-10 mg / m L).Proteins could also be detected in synthetic urine media which is meaningful for clinical application.Thanks to its excellent AIE properties,TPE-Im was able to detect serum on solid media such as gauze,glass and TLC plates which is of potential for latent blood detection in criminal scene.