Annelis O Sánchez has completed her Baccalaureate degree at University of Puerto Rico- Rio Piedras Campus and is currently pursuing her PhD candidate at same institution. She had worked as a Chemist in several pharmaceuticals, and private companies. She has experience as a Chemist in a variety of interdisciplinary areas such as “Clinical, environmental, pedagogy and industrial”. She completed her internship at University of Texas in Austin, where she learned the basis of single particle detection methods.

During the last decades, single particle detection have opened a novel sight for doing electrochemistry. The possibility of detecting single biomolecules, differentiate between a single cancer cell in presence of healthy cells and detecting single viruses are envisioning steps toward the development of biosensor and novel techniques for better understanding of a human’s machinery. More recently, advances in single metal detection of nanoparticles, organic particles and oxide particles have been achieved. Studies in non-homogeneous solutions detecting an emulsion oil droplet has been accomplished. In this research, zero valent iron nanoparticles (nZVI) prompt to oxidation in aqueous media, are detected and characterized by electrochemical techniques using the emulsion droplet single particle approach. During the experiment, it is expected to observe current blips as a result of a current increase when the electroactive modified drop reaches the electrode. ZVI particles are known to be ion sequesters and are used for environmental remediation. Due to this behavior, the nZVI particles are a promising alternative to heavy metal poisoning. Because cancer cells are known to have a higher iron requirement than healthy cells, this fundamental research elucidates how an iron-based cancer biosensor would work. Emulsion oil droplet experiment results can be used to forecast the cell behavior in presence of nZVI. Applications for fundamentally drifted experiments aim to elucidate and characterize novel nanomaterials that are currently used.

Yeon-wook Kim is currently a Professor of Department of Advanced Materials Engineering in Keimyung University, Korea. He is in the Review Board of National Research Foundation of Korea. He has completed his PhD in Materials Science and Engineering from University of Wisconsin-Madison. He studies on the effect of rapidly solidification processing on the martensitic transformation behaviors of Ti-based shape memory alloys. His special interests are in fabrication of porous materials for biomaterials using the rapidly solidified powders and fibers of Ti-based shape memory alloys. He has published more than 90 papers in reputed journals

TiNi shape memory alloy fibers were prepared by a melt overflow process. The martensitic transformation starting temperature of B2→B19’ in the rapidly solidified fibers was 19°C. Cylindrical billets of Ni-rich Ti-Ni alloy with 75% porosity were produced by a vacuum sintering technology using as-cast alloy fibers. The mechanical properties and shape memory properties of the highly porous Ti-Ni alloy is investigated using a compressive test. The plateau of the stress-strain curve was observed at about 7 MPa and resulted in 8% elongation associated with stress-induced B2→B19’ transformation. Because of the high porosity of this specimen, the elastic modulus of about 0.95 GPa could be obtained. It was also found that a recovered strain was 5.9% on heating after the compressive deformation. This recovery of the length is ascribed to the shape memory effect which occurs during the martensitic transformation

Nadja E Solis-Marcano is pursuing her PhD at University of Puerto Rico, Rio Piedras campus. She is currently working with “The development of electrochemical biosensors for the detection of deseases with the characteristics of easy handling, fast detection and minimal use of reagents”. She is also interested in “The fabrication of custom microelectrodes for various applications”.

Colibactin is a genotoxin produced by the polyketide synthase multienzyme (pks genomic island) encountered in the human gut microbiota. Many studies link colibactin production to different kinds of cancers, therefore making it a molecule of interest in the biomedical research field. More specifically, certain strains of Escherichia coli have been found to harbor pks genomic island that induced DNA damage. Here, we developed a PCR mediated-electrochemical protocol to successfully identify the presence of the pks genomic island in DNA samples. For this, pks and non-pks containing E. coli DNA were impedimetrically analyzed before and after amplification through polymerase chain reaction (PCR) protocol. Custom DNA primers were synthesized in order to selectively amplify a specific 400 base pair sequence from the clbN gene from the pks island. Impedance data showed a 97% increase in charge transfer resistance after the protocol was applied for the pks containing samples as opposed to the 15% increase for the non-pks containing DNA samples. Overall, effective identification of the pks genomic island was achieved.

Myreisa Morales Cruz completed her Bachelor Degree in Chemistry and Doctoral studies at University of Puerto Rico, Rio Piedras Campus. She has been awarded with PRLSAMP fellowship from NSF, and RISE fellowship from NHI, during her Doctoral studies. She is currently working on “Microbial ureolysis systems.

Scarcity of clean water is a common problem in many parts of the world. For this reason, water recovery from waste water is essential in the modern world. Major source of nutrients in waste water is urine, approximate 80% of nitrogen, 50% of phosphorus and 9% of the potassium. One of the limitations of reusing wastewater is the presence of urea. The removal of urea is difficult because its small size and lack of charge does not allow the use of common methodologies. This work presents an innovative technique that integrates the use of a carbon anode and a urease positive bacteria, Proteus vulgaris, for the removal of urea. The carbon electrode was modified with platinum nanoparticles for the oxidation of ammonia produced by the bacteria. The modification of the carbon electrode was done by immersion varying the exposition time in the ink and the way the electrode was dried. Cyclic voltammetry was done to characterize the platinum particles and the carbon electrode before and after the modification. SEM images were taken to determine if the Pt particles were dispersed and if the bacteria were attached to the carbon electrode. The carbon electrode was successfully modified when exposed overnight to the Pt ink. The SEM images showed bacteria adhered to the carbon surface.

Diana C Diaz Cartagena is pursuing her PhD at University of Puerto Rico, Rio Piedras Campus. She works at Dr. Cabrera’s laboratory, a laboratory with interest in “Electrochemistry, interfaces and nanotechnology”. Her research project is focused on “developing a biosensor”.

Over the last decade, an increasing number of researchers have focused on developing rapid techniques based on biosensor technology for the detection of various human health related conditions. The use of this technology helps to detect early signs of the disease, such as cancer, in a short period of time with high efficiency. The number of cases diagnosed with this condition is increasing throughout the years due to the unhindered growth of abnormal cells partially caused by an enzyme called telomerase. This enzyme activates and elongates telomeres at the end of the chromosomal DNA, which causes cancer cells to become immortal. Telomerase is present in the vast majority of cancer types, therefore, serves as a biomarker. In this work, we developed a DNA biosensor using self-assembled monolayer technique for detection of telomerase activity in cancer cells. Specifically, we used a robust miniature DNA gold electrode as the sensing platform for the capacitive detection of enzyme binding and DNA elongation processes by telomerase utilizing electrochemical impedance spectroscopy. We measured changes in the capacitance when the surface was exposed to telomerase and to a DNA elongation inhibitor. Also, we studied how heat-shock affects the enzyme activity using charge transfer resistance as the sensing parameter. This system provides advantages in terms of simplicity, efficiency and cost of electrode design and will have a tremendous impact on the biomedical science, filling the absence of methods that can detect telomerase in a direct readout at the point-of-care location using lab-on-a-chip technology.