A Miniaturized Droplet Electrochemical Detection Platform

Electrochemical detection methods are suitable for constructing miniaturized analysis devices due to the advantages,including high sensitivity,easily miniaturization,non-transparent samples detection and low power requirements.To precisely control the solution,ensure the utilization of the samples,and the detection frequency,the fluid manipulation technique such as microfluidic has been introduced to design various miniaturized electrochemical devices.The microfluidic devices have great potential and convenience in analysis of samples with limited volume.However,the complicated fabrication procedure and high cost limit the application of microfluidic chips.The advantage of microfluidic devices is not obvious in routine analytical cases where the samples could be easily obtained,especially in batch detection.Routine analysis requires the miniaturized analytical devices with less sample and reagent consumption,easy manipulation and low cost.Droplet is an effective fluid manipulation technique.It can mix and transfer liquids in short diffusion distances.It has the features of small volume,simple manipulation and the droplet can act as an independent unit.Therefore,droplet provides a method to detect samples with less volume,and can be an effective way to control fluid in miniaturized devices.In this work,a new miniaturized droplet detection platform is designed on the basic of the droplet technique.The suspended droplet detection was used in this device.The rapid and forced mixing of the sample solution and the reagent solution is realized by the surface tension of the droplet coalescing,and each suspension droplet becomes an independent unit without the detection pool.By comparison with daily detection,the self-made miniaturized detection platform has the apparent advantages,including low consumption of the samples and reagents,high analytical frequency,and automation.All together,the device would be applied in routine assay.To illustrate the feasibility and practicability,electrochemical and electrochemilumines-cence detection were systematical studied with the self-made miniaturized detection platform.This work mainly includes the following chapters:Chapter one.Introduction.The characteristics,classification,and significance of the miniaturized analytical device were briefly introduced.The methods of electrochemical detection and the applications of miniaturized electrochemical analytical devices were also described.The research background,research contents,and originality of the work were showed.Chapter two.Construction of miniaturized droplet detection platform and its application in current sensor.The device was firstly applied in the basic electrochemistry system of K3Fe(CN)6 solution,demonstrating the feasibility of the device in detection of current.Next,the sensors of glucose and uric acid have been designed.A good linear relationship between the concentration of glucose(or uric acid)and the response current can be well obtained.Our results are comparable to the previously reported methods.The self-made miniaturized droplet detection platform has the potential to establish a variety of current-miniaturized analytical devices.Chapter three.Application case of undergraduate experimental teaching of miniaturized droplet detection platform.To indicate the practicability,determination of K3Fe(CN)6 by cyclic voltammetry was performed by the self-made miniaturized droplet detection device.Compared with the conventional apparatus,the presented device had the following apparent features,including greater interest for the undergraduate students,lower samples and reagents volume,and more environment friendly.Chapter four.A feasibility study of miniaturized droplet detection platform on the electrochemiluminescence(ECL).The classical ECL system of Ru(bpy)32+-TPA was chosen as model applied in the designed device.The results showed that the ECL intensity of Ru(bpy)32+ has a good linear relationship to the concentration of TPA,which illustrated that the device has great potential in ECL.Chapter five.Summary and perspective.