In the present work, a portable and low-cost planar waveguide based resonance light scattering (RLS) scanner (termed as: PW-RLS scanner) has been developed for microarray detection. The PW-RLS scanner employs a 2 × 4 white light emitting diode array (WLEDA) as the excitation light source, a folded optical path with a complementary metal oxide semiconductor (CMOS) as the signal/image acquisition device and stepper motors with gear drives as the mechanical drive system. The biological binding/recognizing events on the microarray can be detected with an evanescent waveguide-directed illumination and light-scattering label (e.g., nanoparticles) while the microarray slide acts as an evanescent waveguide substrate. The performance of the as-developed PW-RLS scanner has been evaluated by analyzing type 2 diabetes mellitus (T2DM) risk genes. Highly selective and sensitive (less than 1% allele frequency at the attomole-level) T2DM risk gene detection is achieved using single-stranded DNA functionalized gold nanoparticles (ssDNA-GNPs) as detection probes. Additionally, the successful simultaneous analysis of 15 T2DM patient genotypes suggests that the device has great potential for the realization of a personalized diagnostic test for a given disease or patient follow-up.

A peptide microarray-based fluorescent and resonance light scattering (RLS) two readout assay has been developed for screening thrombin inhibitors in blood samples. In this assay, the biotinylated peptide microarray was used as the reaction platform. The peptide C-terminal fragments carrying biotin sites departed from the slide when the biotinylated peptides were digested by thrombin hydrolysis reaction. The hydrolysis progress was labeled by fluorescent and 30-nm peptide-stabilized gold nanoparticles (GNPs) through the biotin-avidin interaction. In the presence of thrombin inhibitors, the hydrolysis reactions were blocked, and the inhibition capability of inhibitors could be detected by detecting fluorescent and RLS signal changes. The half maximal inhibitory concentration (IC50) of thrombin inhibitors in pure thrombin solution and spiked human serum was in order of argatroban < human antithrombin-III (HAT-III) < AEBSF. The absolute differences of IC50 between pure thrombin solution and spiked human serum increased with the decreasing inhibition specificity. The order of the inhibition activities of five compounds (7.5 μM) in human plasma was: argatroban > HAT-III > trypsin inhibitor > E-64 > AEBSF. The reversible or irreversible characters of argatroban and HAT-III have been estimated in human plasma. Compared with experimental data of fluorescent and RLS assay in blood sample, the RLS assay labeled by 30-nm GNPs is proven to be more suitable for the inhibitor detection in complex blood sample.A peptide microarray-based fluorescent and resonance light scattering two-readout assay has been developed for screening thrombin inhibitors in human plasma. Compared with fluorescent assay, the resonance light scattering method labeled by 30-nm gold nanoparticle probes is more suitable for inhibitor study in complex blood samples.

A peptide microarray-based resonance light scattering (RLS) assay with gold nanoparticle probes has been developed for monitoring thrombin generation in human plasma. Thrombophilia, hypocoagulability and normal plasma have been successfully differentiated by the assay.

A peptide microarray-based resonance light scattering (RLS) assay with gold nanoparticle probes has been developed for monitoring thrombin generation in human plasma. Thrombophilia, hypocoagulability and normal plasma have been successfully differentiated by the assay.