The Fundamental Experiment Researches Of Biosensor Based On BLM

Bilayer lipid membrane (BLM) is a perfect model of studying life phenomenon, Its structure is extraordinary similar to that of bio-membranes and it is very easily to be modified. The modified BLM can recognize the corresponding substance very well. Viewed as a perfect sensor membrane, BLM is widely used in biosensor research.Electrochemical method is a simple way to study the electrical properties of the BLM. But it is difficult to distinguish the corresponding currents of BLM from the available data. In addition, the stability of the membranes is one of the key points which limit its usage as real sensors. Both are studied in this paper through many nuporianl experiments which may be viewed as references for further researches.In this paper, the method of probe making was well developed. A stainless wire was pushed into a Teflon bar and the metal surface of the probe was treated with mechanical and chymic methods. Thus the micro structure's cohesive affinity to the probe surfaces were improved. Also, the comparability and repeatability of the data acquired from different experiments were improved too.The resistance of BLM under our experiment conditions was estimated approximately (its upper limit was about 1.26 107-cm2) in this paper. And according to the data obtained, it was pointed out that a real BLM might be a parallel connection of several smaller island BLM. Thus an electrical matrix was put forward of a real BLM. Both are good references of our experiments.To distinguish the very CV current from all those data, some new methods were adopted such as lecithin solution obstructing, air obstructing, reversing and washing methods etc. All were proved to be effective methods by acquiring accordant data.The stability of the BLM may be improved from two aspects. One is to reduce the disturbances from the environments. The other is to improve the adherence strength to the substance of the BLM. In this paper, many methods were adopted to reduce all kinds of disturbances. And modified with cholesterol the stable time was well prolonged to more than 35 days comparable to the unmodified membrane.In this paper, the Current-Voltage characteristics of unmodified s-BLM were tested during its formation. They were processes of gradually becoming small till to relative stable currents. And in the study of the CV characteristics of the BLM modified with L, it showed that IT did act as ion carrier but there was no obvious redox current of s-BLM modified with iodine possibly because of the low content of 1: in the membrane as well as its loss from the BLM. Several possible ways were mentioned to solve the loss problem of I2 in the BLM.Aside, many assistant experiment tools were developed such as the tools to make probes, self-made probes, pre-micro-flow-system, simple temperature control system. All kinds of stands were of great help to the experiments.