A route to low-cost nanoplasmonic biosensor integrated with optofluidic-portable platform

The optofluidic nanoplasmonic biosensors could offer label-free monitoring of biomolecular interactions in real-time with the low consumption of the sample, which stimulate researchers' tremendous interest. To meet the need of the laboratory and clinic testing, the protocols of fabricating nanoplasmonic biosensor and testing processes were detailedly described, which is simple and low-cost. The photolithography, electron beam evaporation, annealing and bonding were applied to fabricate the nanoplasmonic biosensor which integrated with microfluidics on an optofluidic-portable platform. The 9 kinds of samples with different reflective index and antigen/antibody system were utilized to characterize the developed nanoplasmonic biosensor. Meanwhile, the biomarker of the liver cancer also was tested in situ and real time by the optofluidic platform. The detected concentration of the liver cancer antigen and antibody reached 45.24 ng/ml and 25 ng/ml, respectively. This method could improve the diagnosing accuracy in the liver cancer early stage or other serious diseases.