Shramik Sengupta

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We report a novel buffer electric and dielectric relaxation time tuning technique, coupled with a glutaraldehyde (Glt.) cross-linking cell fixation reaction that allows for sensitive dielectrophoretic analysis and discrimination of bovine red blood cells of different starvation age. Guided by a single-shell oblate spheroid model, a zwitterion buffer(More)
The technique described enables the user to detect the presence and proliferation of bacteria through an increase in the bulk capacitance (C) of the suspension, which is proportional to the bacteria count, at practical frequencies less than 1 MHz. The geometry of the micro-capillary design employed increases the bulk resistance (R) of the medium, thus(More)
This paper presents a detailed electrochemical impedance spectroscopy and cyclic voltammetry (CV) investigation into the electrocatalytic activity of ultrafine (i.e., smaller than 2 nm) platinum (Pt) nanoparticles generated on a fluorine-doped tin oxide (FTO) surface via room temperature tilted target sputter deposition. In particular, the Pt-decorated FTO(More)
The development of genetic detection protocols for field applications is an important aspect of modern medical diagnostic technology and environmental monitoring. In this paper, we report a rapid, portable, and inexpensive DNA hybridization technique using a bead-based microfluidic platform that functions by passing fluorescently labeled target DNA through(More)
Melanoma is the deadliest form of skin cancer, yet current diagnostic methods are unable to detect early onset of metastatic disease. Patients must wait until macroscopic secondary tumors form before malignancy can be diagnosed and treatment prescribed. Detection of cells that have broken off the original tumor and travel through the blood or lymph system(More)
When separating two species with similar densities but differing sedimentation velocities (because of differences in size), centrifugal elutriation is generally the method of choice. However, a major drawback to this approach is the requirement for specialized equipment. Here, we present a new method that achieves similar separations using standard benchtop(More)
Polyethylene terephthalate (PET) mesh is one of the most commonly used synthetic biomaterials for tension-free hernia repair. In an effort to improve the biocompatibility of PET mesh, gold nanoparticles (AuNP) in various concentrations were conjugated to the PET surface to develop PET-AuNP scaffolds. These novel scaffolds were characterized with Fourier(More)
We present a novel electrical method for detecting viable bacteria in blood cultures that is 4 to 10 times faster than continuous monitoring blood culture systems (CMBCS) like the Bactec system. Proliferating bacteria are detected via an increase in the bulk capacitance of suspensions, and the threshold concentration for detection is ∼ 10(4) CFU/ml(More)
Bacterial colonization and biofilm formation on an orthopedic implant surface is one of the worst possible outcomes of orthopedic intervention in terms of both patient prognosis and healthcare costs. Making the problem even more vexing is the fact that infections are often caused by events beyond the control of the operating surgeon and may manifest weeks(More)
A lag after pulsed separation (LAPS) meter was previously developed to measure flow rates of protein solutions. The LAPS meter operates on the time-of-flight principle. An upstream event (electrophoretic concentration of the particles in one section of the device) is detected downstream (by change in ac resistance). The time lag between the event and its(More)