Design Of Microfluidic Paper Chip For Bladder Cancer Detection

Background: As a high mortality and recurrence-prone urological neoplasm,in vitro diagnosis of bladder cancer has been a research hotspot.The existing microfluidic chip device for bladder cancer detection has many problems,such as complex preparation and operation,long detection time and the need for dedicated terminal detection equipment.In this paper,a paper-based microfluidic chip for combined detection of specific tumor marker proteins in urine is proposed to achieve a convenient and rapid detection of bladder cancer.Material and Methods: Based on the principle of the colloidal gold technique of enzyme-linked immunosorbent assay(ELISA),a paper chip was designed to detect bladder cancer marker protein nuclear matrix protein 22(NMP22)and bladder cancer antigen(BTA)in urine samples.The structure of the chip was composed of glass cellulose membrane,polyester membrane,nitrocellulose membrane and absorbent paper,which were made by wax printing method.Each part was connected by a supporting bottom plate.The suitable pairs of NMP-22 and BTA antibodies for colloidal gold labeling were screened through the ELISA test based on antigen-antibody immune reaction,and the optimal pH value and antibody concentration of colloidal gold labeling were explored.The paper chip was validated by the standard antigen,and then the two tumor marker proteins were detected using the patient's urine samples to test the actual effect of the paper chip.Results:(1)The application of wax printing method significantly improved the efficiency of paper chip fabrication,and paraffin could effectively isolate the two detection channels;(2)The optimal pH of colloidal gold labeled NMP22 antibody was 7.5,and the amount of antibody was 1.0 ?g/100 ?L;and the optimal pH of labeled BTA antibody was 7.7,and the optimal amount of antibody was 0.8 ?g/100 ?L;(3)When applied the paper chip in clinical application,the urine samples of 11 patients with bladder cancer were tested positive in 10 cases,and the test results of normal people were all negative.In addition,the whole process only took 1-3 minutes.Conclusions: In this paper,a paper chip for the combined detection of two bladder cancer markers in urine samples was successfully constructed.The results were presented with clear strips visible to the naked eye by colloidal gold method,which avoided the need for special analytical instruments.At the same time,it has the advantages of simple manufacture,fast operation,low cost and portability.The chip has successfully realized the detection of bladder cancer with urine sample,which enhanced the feasibility of the paper chip in practical application and could assist users in self-detection of bladder cancer.