Study On The Application Of Silk Fibroin Microneedle In The Detection Of Blood Glucose Concentration

Silk fiber has been widely used in many fields for a long time.It has been used as surgical suture and gauze for decades.Silk fibroin has many advantages because of its unique structure and performance,which has attracted many researchers’ interest.In this paper,silk fibroin biomaterials were used to prepare the matrix of microneedles,which formed a three electrode structure for the transdermal detection of glucose concentration.First of all,the matrix of micro needle sensor should have good penetration and conformability.Therefore,by adding D-sorbitol,xylitol,erythritol and proline to change the structure(degree of crystallization)of microneedles,the breaking strength,dissolution swelling and shape retention of microneedles can be adjusted.The results show that the addition of D-sorbitol in four kinds of small molecules can obtain the matrix of silk fibroin microneedles with good penetration and insolubility.On this basis,D-sorbitol/silk fibroin was used as the matrix material of micropipette,and glucose oxidase(God)was added as the catalyst of glucose molecular oxidation to prepare micropipette detection electrode.At the same time,the effects of metal catalyst,redox potential,scanning rate,d-mountain/SF ratio,the best use of God,temperature and pH on the current were explored.The results showed that the optimum conditions were platinum wire catalysis,scanning rate 100mV/s,God concentration 5u/needle,pH=7,t=35℃,and the maximum current was produced.In order to further explore the glucose detection range,step-by-step test,anti-interference,24-hour detection and storage stability,we selected the best conditions to prepare the micro needle matrix and combined it into a sensor.The results show that the linear range of the sensor is 1.7～10.4mm,the step test is obvious,and the anti-interference is strong.Due to the unique structure of silk fibroin,an environment conducive to the stabilization of glucose oxidase has been established,so that the God can keep the activity stable for a long time and can realize 24-hour continuous monitoring.