Paper-based Device For Metal In-situ Growth And Its Application In Electrochemical Sensor

Under the driving of the rapid development of science and technology,early preclinical diagnosis and warning for disease has become a necessary trend.There are two ways in common clinical diagnosis.One is that patient must to check up in hospital using expensive equipments and the other one is that people need to detect in home using portable instruments.The former approach is expensive and not suitable for the developing and remote area.The later method is simple and convenient,but this method with low accuracy,and thus limits its development.Paper based devices,since developed by Whitesides,have caused extensive concern and are rapidly consolidated in biosensors.Up to now,various paper based devices were developed and used for detection of DNA,antigen-antibody,glucose,cells,H₂O₂ and H₂ S.Various noble metals were grown on the surface of the paper in situ and used to constructed paper based devices.The antigens,endogenous H₂O₂ and H₂ S were tested,which laid the foundation for early preclinical warning for disease.?1?A new paper chip was designed and Pt-Zn O nanoparticles were grown on it.A dual photoelectrochemical/colorimetric cyto-analysis format was first introduced into a microfluidic paper-based analytical device for synchronous sensitive and visual detection of H₂O₂ released from tumor cells.?2?The Au@Pt nanoparticles were grown firstly on the paper fiber and used as substrate of the biosensor.Under the help of CCD imaging technique,real-time visual determination of H₂ S released from multiple cancer cells was achieved for the first time.?3?Nanoporous Pt particles were grown on the surface of the paper from Pt NP seeds,which improveed electron conduction and provided a biocompatible microenvironment for the immobilization of antibodies,resulting in the first signal amplification.The metal ions loaded on the L-cysteine capped flower-like Au nanoparticles?Au–Cys?were prepared and used as carrier for two tumor biomarkers,resulting in the second signal amplification.The metal ion labels could be detected directly through differential pulse voltammetry and the distinct voltammetric peaks had a close relationship with each sandwich-type immunoreaction.Therefore,a novel 3D paper based device for simultaneously detecting carcinoembryonic antigen and alpha-fetoprotein with wider linear ranges was developed.?4?The Au@Pd nanoparticles,with high catalytic performance,were grown on paper.Au@Pt core–shell nanoparticles were used as carriers for electroactive and biocompatible cationic dye methylene blue?MB?and glucose oxidase attachment.On the basis of the dual amplified electrochemical signal,the lab on paper device has a sensitive response to carcinoembryonic antigen.