We report a method for rapid detection and analysis of biological and environmental analytes by microwave-accelerated bioassays (MABs) and a novel MATLAB-based image processing of colorimetric signals. In this regard, colorimetric bioassays for histidine-rich protein 2 (HRP-2) and microcystin-leucine arginine (MC-LR) toxin were carried out using MABs and without microwave heating (i.e, gold standard bioassays). Our MATLAB-based detection method is based on the direct correlation of color intensity of a solution calculated from images captured with a smartphone with the concentration of the biomolecule of interest using a MATLAB code developed in-house. We demonstrated that our MATLAB-based detection method can yield bioassay sensitivity comparable to the colorimetric gold standard tool, i.e., UV-Visible spectroscopy. In addition, colorimetric bioassay time for the HRP-2 assay (used in malaria diagnosis) and colorimetric MC-LR bioassay (used in MC-LR toxin diagnosis) was reduced from up to 2 hours at room temperature without microwave heating to 15 minutes using the MABs technique.

Investigation of the bi-directional relationship between natural killer (NK) cells and plasmacytoid dendritic cells (pDCs) is critical in understanding antiviral immunity. In the present study, we determined whether the tumor necrosis factor apoptosis-inducing ligand (TRAIL) pathway was responsible for increased apoptosis of pDCs in hepatitis C virus (HCV) infection. We stimulated peripheral blood mononuclear cells (PBMCs) with recombinant HCV core protein within 12 hours to measure the relative expression of tumor necrosis factor apoptosis-inducing receptor 1 (TRAIL-R1) and TRAIL-R2 in pDCs using flow cytometry and image cytometry. We also measured the relative expression of TRAIL in NK cells after stimulation with recombinant HCV core protein using flow cytometry and image cytometry. Using flow cytometry, our results show that within 12 hours of stimulation, HCV core protein increases TRAIL-R1 on pDCs by 0.01%, CD56 expression by 0.66%, and TRAIL expression by 0.66%, in NK cells as compared to unstimulated PBMCs. ELISA and fluorescence spectroscopy results showed that HCV core protein decreases Bcl-2 expression in PBMCs and in pDCs by 36% and 3%, respectively. Our results suggest that HCV core protein increases NK cell deletion of pDCs, independent of the Bcl-2 pathway, contributing to HCV viral escape from immune responses, which may result in chronic HCV infection.

Effect of intermittent monomode microwave heating on the crystallization of glutathione (GSH) and lysozyme on indium tin oxide (ITO) films using the metal-assisted and microwave-accelerated evaporative crystallization (MA-MAEC) technique was investigated. Intermittent time intervals of 5, 10, 15, 30, 40, 60, 120, 180, 240 min and 30, 40, 60, 120, 180, 240 min were employed for microwave heating of solutions of GSH (500 mg/mL) and lysozyme (40 mg/mL) using a monomode microwave source at 70 W, respectively. Optical microscopy and ImageJ software were employed to quantify and compare the size and number of GSH and lysozyme crystals grown at different microwave heating time intervals. The rate of crystallization for GSH crystals was found to be the fastest at ~ 7.52 μm/min for the 5 min interval of microwave heating and decreased to 0.57 μm/min as the time interval of microwave heating was increased to 240 min. The rate of crystallization for lysozyme crystals was found to be 0.20 ~ 0.27 μm/min for 30-120 min of microwave heating and decreased to 0.07 μm/min as the time interval of microwave heating was increased to 240 min. Intermittent microwave heating of GSH and lysozyme solutions were found to have a minimal influence on the size and count of the crystals produced. X-ray crystallography studies and Fourier transform infrared (FTIR) spectroscopic analysis of grown crystals confirmed that the duration of microwave heating have no or little effect on the crystal morphology and molecular structure of biomolecules studied.

A robust innate and adaptive immune response is essential to viral clearance. Hepatitis C virus (HCV) infection typically leads to alteration of the innate and adaptive immune response, which is caused by interaction of HCV core protein with various host factors. It is important to investigate the alterations to the immune response during the transition from acute HCV to chronic HCV infection to develop better therapeutic methods for HCV infection. In this work, to determine whether HCV viral persistence occurs via tumor necrosis apoptosis-inducing ligand (TRAIL)-mediated apoptosis, we stimulated peripheral blood mononuclear cells (PBMCs) with recombinant HCV core protein within 12 h to measure the relative expression of death receptors 4 and 5 (DR4 and DR5) in PBMCs. We show that recombinant HCV core protein causes increased DR4 and DR5 expression in PBMCs. We also show that TRAIL interacts with DR4 and DR5 after cleavage of membrane-bound TRAIL yielding soluble TRAIL. Our results show that HCV core protein increases PBMC susceptibility to apoptosis and may cause increased TRAIL pathway activity within 12 h of infection. In addition, we observed that increased death receptor expression may contribute to HCV pathogenesis, as typically observed in chronically HCV-infected individuals.

The use of indium tin oxide (ITO) and focused monomode microwave heating for the ultra-rapid crystallization of L-alanine (a model amino acid) is reported. Commercially available ITO dots (< 5 mm) attached to blank poly(methyl)methacrylate (PMMA, 5 cm in diameter with 21-well silicon isolators: referred to as the iCrystal plates) were found to withstand prolonged microwave heating during crystallization experiments. Crystallization of L-alanine was performed at room temperature (a control experiment), with the use of two microwave sources: a 2.45 GHz conventional microwave (900 W, power level 1, a control experiment) and 8 GHz (20 W) solid state, monomode microwave source with an applicator tip that focuses the microwave field to a 5-mm cavity. Initial appearance of L-alanine crystals and on iCrystal plates with ITO dots took 47 ± 2.9 min, 12 ± 7.6 min and 1.5 ± 0.5 min at room temperature, using a conventional microwave and focused monomode microwave heating, respectively. Complete evaporation of the solvent using the focused microwaves was achieved in 3.2 ± 0.5 min, which is ~52-fold and ~172-fold faster than that observed at room temperature and using conventional microwave heating, respectively. The size and number of L-alanine crystals was dependent on the type of the 21-well iCrystal plates and the microwave heating method: 33 crystals of 585 ± 137 μm in size at room temperature > 37 crystals of 542 ± 100 μm in size with conventional microwave heating > 331 crystals of 311 ± 190 μm in size with focused monomode microwave. FTIR, optical microscopy and powder X-ray diffraction analysis showed that the chemical composition and crystallinity of the L-alanine crystals did not change when exposed to microwave heating and ITO surfaces. In addition, theoretical simulations for the binding of L-alanine molecules to ITO and other metals showed the predicted nature of hydrogen bonds formed between L-alanine and these surfaces.

We present the synthesis, characterization, biological and sensing applications of a Schiff base, (E)-3-((5-bromo-2-hydroxy-3-methoxycyclohexa-1, 3-dienyl)methyleneamino)-6-(hydroxymethyl)-tetrahydro-2H-pyran-2,4,5-triol. Characterization of the title compound was carried out using theoretical quantum-mechanical calculations and experimental spectroscopic methods. The molecular structure of the title compound was confirmed using NMR and FTIR, which was in good agreement with the structure predicted by the theoretical calculations. The title compound was evaluated for its ability to detect anions in DMSO and on a solid surface and for its antimicrobial activity against several common microorganisms.

The effect of metal surfaces on the crystallization of lysozyme using the Metal-Assisted and Microwave-Accelerated Evaporative Crystallization (MA-MAEC) technique and a monomode microwave system is described. Our microwave system (is called the iCrystal system hereafter for brevity) is comprised of a 100 W variable power monomode microwave source, a monomode cavity, fiber optic temperature probes and digital cameras. Crystallization of lysozyme (a model protein) was conducted using the iCrystal system on four different types of circular crystallization plates with 21-well sample capacity (i.e., crystallization plates): (ⅰ) blank: a continuous surface without a metal, (ⅱ) silver nanoparticle films (SNFs): a discontinuous metal film, (ⅲ) iron nano-columns: a semi-continuous metal film, and (ⅳ) indium tin oxide (ITO): a continuous metal film. Lysozyme crystals grown on all crystallization plates were characterized by X-ray crystallography and found to be X-ray diffraction quality. The use of iron nano-columns afforded for the growth of largest number of lysozyme crystals with a narrow size distribution. ITO-modified crystallization plates were deemed to be best of all the crystallization plates based on the observations that lysozyme crystals were grown at the shortest time (370 ± 36 minutes) with a narrow size distribution up to 460 m in size.

We present a platform technology, called Metal-Assisted and Microwave-Accelerated Decrystallization (MAMAD), which is based on the use of dispersion of gold colloids with low power microwave heating to decrystallize organic and biological crystals attached to surfaces. Uric acid crystals were chosen as model target crystals to be decrystallized using MAMAD technique. A two-step procedure was employed: 1) growth of uric acid crystals on a model surface (collagen films coated on to glass slides to simulate a human joint) at room temperature and 2) de-crystallization of uric acid crystals in synovial fluid (in vitro) using silver and gold colloids in conjunction with low power microwave heating. Using the MAMAD technique with gold colloids, the number of uric acid crystals was drastically reduced by 80% after 10 min, where the average size of the uric acid crystals was reduced from 125 μm to 50 μm. In control experiments and with silver colloids that aggregated from the solution, the size and number of uric crystals remained unchanged, indicating that the combined use of only metal colloids in solution and microwave heating is effective for the de-crystallization of uric acid crystals in biological media.

We report the enhancement of chemiluminescence response of horseradish peroxidase (HRP) in bioassays by plasmonic surfaces, which are comprised of (i) silver island films (SIFs) and (ii) metal thin films (silver, gold, copper, and nickel, 1 nm thick) deposited onto glass slides. A model bioassay, based on the interactions of avidin-modified HRP with a monolayer of biotinylated poly(ethylene-glycol)-amine, was employed to evaluate the ability of plasmonic surfaces to enhance chemiluminescence response of HRP. Chemiluminescence response of HRP in model bioassays were increased up to ~3.7-fold as compared to the control samples (i.e. glass slides without plasmonic nanoparticles), where the largest enhancement of the chemiluminescence response was observed on SIFs with high loading. These findings allowed us to demonstrate the use of SIFs (high loading) for the detection of a biologically relevant target protein (glial fibrillary acidic protein or GFAP), where the chemiluminescence response of the standard bioassay for GFAP was enhanced up to ~50% as compared to bioassay on glass slides.

In this study, we demonstrated a unique application of our Metal-Assisted and Microwave-Accelerated Evaporative Crystallization (MA-MAEC) technique for the de-crystallization of uric acid crystals, which causes gout in humans when monosodium urate crystals accumulate in the synovial fluid found in the joints of bones. Given the shortcomings of the existing treatments for gout, we investigated whether the MA-MAEC technique can offer an alternative solution to the treatment of gout. Our technique is based on the use of metal nanoparticles (i.e., gold colloids) with low microwave heating to accelerate the de-crystallization process. In this regard, we employed a two- step process; (ⅰ) crystallization of uric acid on glass slides, which act as a solid platform to mimic a bone, (ⅱ) de-crystallization of uric acid crystals on glass slides with the addition of gold colloids and low power microwave heating, which act as “nano-bullets” when microwave heated in a solution. We observed that the size and number of the uric acid crystals were reduced by >60% within 10 minutes of low power microwave heating. In addition, the use of gold colloids without microwave heating (i.e. control experiment) did not result in the de-crystallization of the uric acid crystals, which proves the utility of our MA-MAEC technique in the de-crystallization of uric acid.