Study On Dopamine Detection In PC12 Cells By Photoelectric Biosensor With Nano-TiO₂ Material

Dopamine is one of the most abundant catecholamine neurotransmitters in the brain,which has many physiological functions that regulate the central nervous system.At the same time,as a neurotransmitter that delivers exciting and happy messages,it can treat depression and help improve memory for Alzheimer’s disease.In addition,it can be used as a drug used in the treatment of cardiovascular disease,cardiac surgery,myocardial infarction,renal failure and congestive heart failure caused by hypertension,bronchial asthma,shock and heart disease.However,when dopamine is insufficient,people lose control of the muscles,which can cause the patient’s hands and feet to vibrate independently and cause Parkinson’s disease.Therefore,to establish an accurate method for the detection of dopamine in vivo can help to understand the development of disease and control the disease.It has profound theoretical significance and clinical application value.In recent years,photoelectroch emical biosensors have the advantages of fast response,high sensitivity,simple operation,miniaturization and low cost,and provide a new technique for detection of small molecules in cells.In this paper,photoelectrochemical biosensors based on TiO₂ or TiO₂@PDA nanostructured materials were constructed and used for the detection of DA in PC12cells.The sensitivity and stability of the sensors were also investigated.The main research work in this paper includes:One:The detection of DA in PC12 cells based on nano TiO₂ photoelectric biosensorThe photoelectrochemical biosensor based on TiO₂ nanomaterials was constructe d,and characterized by using scanning electron microscope（SEM）,transmission electron microscopy（TEM）,X-ray diffraction（XRD）,Raman spectroscopy.Under optimizing the experimental conditions,this sensor has a good linear relationship with the detection of DA using amperometic–time curve method,and the detection concentration in the range of 6×10^-7-1×10^-55 mol/L,the resulting linear equation is△I（nA）=14.22C_DA（μmol/L）+11.95,R²=0.993 within the scope of detection limit（S/N=3）reached 1.2×10^-88 mol/L.This sensor was used for the detection of DA in neuronal cells（PC12）.The results showed that the concentration of DA in PC12 cells（～1×10⁵ cells/mL）was 3.4μmol/L.Two:The detection of DA in PC12 cells based on nano TiO₂@PDA photoelectric biosensorThe photoelectrochemical biosensor based on nanometer TiO₂@PDA was modified,and characterized by scanning electron microscope（SEM）,transmission electron microscopy（TEM）,X-ray diffraction（XRD）,Raman spectroscopy,Fourier Transform infrared spectroscopy（FT-IR）.In the optimal condition,The sensor can realize the DA detection using amperometic–time curve method,The detect concentrations between 1×10^-88 mol/L and 8×10^-66 mol/L have good linear relationship,the resulting linear equation is△I（nA）=49.56C_DA（μmol/L）-2.353,R²=0.999,the detection limit（S/N=3）reached 2.5×10^-99 mol/L,The sensor is also used for the detection of the DA content in PC12 cells.The results showed that the concentration of DA in PC12 cells（～4×10⁴ cells/mL）was 1.7μmol/L.