title: Integration of gold nanoparticles in PDMS microfluidics for lab-on-a-chip plasmonic biosensing of growth hormones.
abstract: Gold nanoparticles were synthesized in a poly(dimethylsiloxane) (PDMS) microfluidic chip by using an in-situ method, on the basis of reductive properties of the cross-linking agent of PDMS. The proposed integrated device was further used as a sensitive and low-cost LSPR-based biosensor for the detection of polypeptides. Synthesis of nanoparticles in the microfluidic environment resulted in improvement of size distribution with only 8% variation, compared with the macro-environment that yields about 67% variation in size. The chemical kinetics of the in-situ reaction in the microfluidic environment was studied in detail and compared with the reaction carried out at the macro-scale. The effect of temperature and gold precursor concentration on the kinetics of the reaction was investigated and the apparent activation energy was estimated to be Ea*=30 kJ/mol. The sensitivity test revealed that the proposed sensor has a high sensitivity of 74 nm/RIU to the surrounding medium. The sensing of bovine growth hormone also known as bovine somatotropin (bST) shows that the proposed biosensor can reach a detection limit of as low as 3.7 ng/ml (185 pM). The results demonstrate the successful integration of microfluidics and nanoparticles which provides a potential alternative for protein detection in clinical diagnostics.
authors: Optical-Bio Microsystems Laboratory, Department of Mechanical Engineering, Concordia University, Montreal, Quebec, Canada.
authors: Hamid
authors: H
authors: SadAbadi
authors: Simona
authors: S
authors: Badilescu
authors: Muthukumaran
authors: M
authors: Packirisamy
authors: Rolf
authors: R
authors: Wüthrich
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation*; D002417:Cattle; D004129:Dimethylpolysiloxanes / Q000737:chemistry*; D004867:Equipment Design; D006046:Gold / Q000737:chemistry*; D013006:Growth Hormone / Q000032:analysis*; D057230:Limit of Detection; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D053758:Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure
chemical_list: D004129:Dimethylpolysiloxanes; D006046:Gold; D013006:Growth Hormone