Matthew Stensberg
Purdue University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Matthew Stensberg.
Nanomedicine: Nanotechnology, Biology and Medicine | 2011
Matthew Stensberg; Qingshan Wei; Eric S. McLamore; D.M. Porterfield; Alexander Wei; Maria S. Sepúlveda
Silver nanoparticles (Ag NPs) are becoming increasingly prevalent in consumer products as antibacterial agents. The increased use of Ag NP-enhanced products may lead to an increase in toxic levels of environmental silver, but regulatory control over the use or disposal of such products is lagging due to insufficient assessment on the toxicology of Ag NPs and their rate of release into the environment. In this article we discuss recent research on the transport, activity and fate of Ag NPs at the cellular and organismic level, in conjunction with traditional and recently established methods of nanoparticle characterization. We include several proposed mechanisms of cytotoxicity based on such studies, as well as new opportunities for investigating the uptake and fate of Ag NPs in living systems.
Nanotoxicology | 2014
Matthew Stensberg; Rajtarun Madangopal; Gowri Yale; Qingshan Wei; Hugo Ochoa-Acuña; Alexander Wei; Eric S. McLamore; Jenna L. Rickus; D. Marshall Porterfield; Maria S. Sepúlveda
Abstract Silver nanoparticles (Ag NPs) are gaining popularity as bactericidal agents in commercial products; however, the mechanisms of toxicity (MOT) of Ag NPs to other organisms are not fully understood. It is the goal of this research to determine differences in MOT induced by ionic Ag+ and Ag NPs in Daphnia magna, by incorporating a battery of traditional and novel methods. Daphnia embryos were exposed to sublethal concentrations of AgNO3 and Ag NPs (130–650 ng/L), with uptake of the latter confirmed by confocal reflectance microscopy. Mitochondrial function was non-invasively monitored by measuring proton flux using self-referencing microsensors. Proton flux measurements revealed that while both forms of silver significantly affected proton efflux, the change induced by Ag NPs was greater than that of Ag+. This could be correlated with the effects of Ag NPs on mitochondrial dysfunction, as determined by confocal fluorescence microscopy and JC-1, an indicator of mitochondrial permeability. However, Ag+ was more efficient than Ag NPs at displacing Na+ within embryonic Daphnia, based on inductively coupled plasma-mass spectroscopy (ICP-MS) analysis. The abnormalities in mitochondrial activity for Ag NP-exposed organisms suggest a nanoparticle-specific MOT, distinct from that induced by Ag ions. We propose that the MOT of each form of silver are complementary, and can act in synergy to produce a greater toxic response overall.
ieee sensors | 2012
Rajtarun Madangopal; Matthew Stensberg; Marshall Porterfield; Jenna L. Rickus; Nicholas Pulliam
A novel method for spatially controlled layer-by-layer assembly of enzyme-based amperometric biosensors was developed for multi-analyte sensing with high spatial and temporal resolution. Stereo-electrodes with 75 μm tip separation and 1-3 μm tip size were functionalized using a simple three-step electrodeposition scheme to produce biosensors for simultaneous detection of glucose and lactate. Layers of nanostructured platinum, enzyme-doped conductive polymer poly(3,4-ethylenedioxythiophene) [PEDOT] and non-conductive polymer poly(o-aminophenol) [PoAP] were electrodeposited to achieve increased electroactive surface area, fine control over site and quantity of enzyme, and reduced interference. The resulting dual-electrode sensors showed good linear range, fast response times and negligible crosstalk. The proposed scheme can be easily expanded to multi-electrode systems and is adaptable to lab-on-chip platforms for a wide range of analytes.
Proceedings of SPIE | 2010
Eric S. McLamore; Matthew Stensberg; Gowri Yale; Hugo Ochoa-Acuña; Maria S. Sepúlveda; Xuanhao Sun; Ozan Akkus; D.M. Porterfield
Image subtraction has been an extremely useful tool for capturing subtle changes in pixel intensity with extremely high temporal resolution, and has been used for decades in the astronomy and metal corrosion fields. However, to date, image subtraction has not been used as a mainstream technique for investigating morphological changes in cells, tissues, or whole organisms. We introduce a user-friendly differential imaging technique for monitoring real time (~msec) changes in morphology within the micrometer to millimeter spatial scale. The technique is demonstrated by measuring morphological changes morphology for biomedical (bone stress), agricultural (crop root elongation), and environmental (zooplankton ecotoxicology) applications. Subtle changes in growth that would typically only be observed by highly skilled experts are easily resolved via image subtraction and the use of convolution kernels. When coupled with techniques characterizing real time biochemical transport (e.g., respiration, ion/substrate transport), physiology can be directly quantified with a high temporal and spatial resolution. Because of the ease of use, this technique can be readily applied to any field of science concerned with bridging the gap between form and function.
Proceedings of SPIE | 2015
Leyla Nesrin Kahyaoglu; Rajtarun Madangopal; Matthew Stensberg; Jenna L. Rickus
Recent advances in miniaturization and analyte-sensitive fluorescent indicators make optical fiber biosensors promising alternatives to microelectrodes. Optical sensing offers several advantages over electrochemical methods including increased stability and better spatial control to monitor physiological processes at cellular resolutions. The distal end of an optical fiber can be functionalized with different fluorophore/polymer combinations through mechanical, dip-coating or photopolymerization techniques. Unlike mechanical and dip-coating schemes, photopolymerization can spatially confine the sensing layer in the vicinity of light in a more reproducible and controllable manner. The objective of this study was to fabricate microscale fluorescence lifetime based optrodes using UV-induced photopolymerization. Six commercially available acrylate based monomers were investigated for stable entrapment of the oxygen sensitive porphyrin dye (PtTFPP) dye via photopolymerization at the end of optical fibers. Of these, the acrylate-functionalized alkoxysilane monomer, 3-methacryloxypropyl-trimethoxysilane (tradename Dynasylan MEMO) showed maximal response to changes in oxygen concentration. Dye-doped polymer microtips were grown at the ends 50 μm optical fibers and sensitivity and response time were optimized by varying both the concentration of doped dye and the excitation power used for polymerization. The resulting sensors showed linear response within the physiologically relevant range of oxygen concentrations and fast response times. While applied here to oxygen sensing, the photopolymer formulation and process parameters described are compatible with a wide range of available organic dyes and can be used to pattern arrays of spots, needles or more complex shapes at high spatial resolution.
Biosensors for Medical Applications | 2012
Jonathan C. Claussen; Jin Shi; Chandra Sekhar Rout; Mayra S. Artiles; M.M. Roushar; Matthew Stensberg; D. Marshall Porterfield; Timothy S. Fisher
Abstract: Nanomaterials such as carbon nanotubes, graphene, metal nanoparticles, and hybrid carbon/metal nanoparticle structures display remarkable properties. In particular, the chemical, electrical, and electrochemical properties of these nanomaterials have significantly improved biosensor performance. Perhaps the greatest advances in nano-sized biosensors have been achieved in electrochemical biosensing. Nanomaterials incorporated into electrochemical biosensors have greatly enhanced their sensitivity, linear sensing range, and detection limit. Diverse ‘top-down’ and ‘bottom-up’ fabrication techniques have been utilized to incorporate nanomaterials into biosensor construction. Herein, we present the latest advances in the field of nano-sized biosensors, explore their remarkable properties, present their distinct fabrication protocols, and discuss their performance.
Sensors and Actuators B-chemical | 2011
Eric S. McLamore; Matthew Stensberg; Maria S. Sepúlveda; W. Zhang; Margaret Banks; D.M. Porterfield
Water Environment Research | 2014
Wen Zhang; Eric S. McLamore; Wu R; Matthew Stensberg; D.M. Porterfield; Margaret Banks
Environmental Science and Pollution Research | 2014
Matthew Stensberg; Michael Zeitchek; Kul Inn; Eric S. McLamore; D. Marshall Porterfield; Maria S. Sepúlveda
PMC | 2013
David Benjamin Jaroch; Jing Lu; Rajtarun Madangopal; Natalie D. Stull; Matthew Stensberg; Jin Shi; Jennifer L. Kahn; Ruth Herrera-Perez; Michael Zeitchek; Jennifer Sturgis; J. Paul Robinson; Mervin C. Yoder; D. Marshall Porterfield; Raghavendra G. Mirmira; Jenna L. Rickus