Development Of Automatic Multi-channel SPR Detecting Instrument

The Surface Plasmon Resonance detection method has the advantage of without sample labeled, requiring less sample, real-time dynamic detection and high sensitivity compared with traditional means of detection. So it was widely used in chemistry, biometrics, environmental monitor, food detection, clinic diagnosis, and medicine.However, commercial SPR instruments are mostly for laboratory analysis of large precision instruments now. In order to obtain better measurement accuracy and automatic testing capacity, their optical system and automatic injection system are more complicated, which limit their promotion of use. Therefore, the development of a fully automated, highly sensitive, low-cost SPR detection equipment, will absolutely have enormous social and economic benefits.A self-developed automatic dual-channel detecting instrument based on SPR principle was presented in this paper. This instrument was constructed by the sample-load system, the sample-send system, SPR sensor and control circuit. Formed by a sample injection needle that can move up and down and a sample plate, the sample-load system can realize the measurements of 15 kinds of samples, and the automatic cleaning of the sample injection needle. The sample-send system consisted of two precision syringe pumps and a microelectric valve, which ensured that there is always solution flowing through the SPR sensor surface during the automatic sample injection process. The whole sampling process was jointly accomplished by sample-load system, the sample-send system and the control circuit. Applying two section of air to isolate, it separated the sample from the buffer or the regenerated liquid, and then reduced the instrument's measurement error. Sensor is the kernel of the whole instrument, and a self-designed dual-channel SPR sensor was applied to this detecting instrument. The control circuit mainly included:the MCU(microcontroller unit) control unit with the core of C8051F020 to control the automatic sampling system of pumps and valves, USB2.0 interface circuit with the core of CY7C68013 to realize the dual-communication between PC and MCU, the real-time data acquisition and uploading to the PC for further analysis and processing. The results of the concentration detecting experiments and data analysis of sucrose showed that this system has good measurement accuracy, high sensitivity and stability.