5^th Euro Biosensors & Bioelectronics Conference June 30-01, 2016 Valencia, Spain

Michael Müller has completed his Diploma in Biology from Saarland University. After working as a researcher at Korea Institute of Science and Technology, Europe, he is currently doing his PhD degree there.

On this poster, we present an amperometric Cytochrome P450 3A4 (CYP3A4) Biosensor. Human hepatic Cytochrome P450s are responsible for the metabolism of the major part of xenobiotics and, among those, CYP3A4 shows the largest substrate range. This makes this enzyme an interesting target for research in many fields and is a standard test object in drug discovery. To connect the enzyme efficiently to the gold electrode PAMAM, dendrimers of generation 4 have been used that were futher modified with sub nanometer gold particles forming organic/inorganic nanocomposites. The biosensor itself was constructed by using a layer-by-layer assembly method where discrete monolayers of the respected compounds were immobilized in a sequential way due to electrostatic interactions between charged moieties. Assembly of the individual layers was monitored by QCM and FTIR spectroscopy and surface morphologies were observed by AFM. A highly reproducible assembly could be established showing less than 10% variability and in good agreement with theoretically established values for compound monolayer formation. To test the applicability of the CYP3A4 biosensor, cyclic voltammetry (CV) was used to establish electron transfer rate ks as well as the amount of electroactive surface-constraint enzyme. Furthermore, CV was used to detect CYP3A4 substrate caffeine to ascertain detection limit (5µM) and linear range (25-100µM).

Mahnaz M Abdi received her PhD in Material Chemistry from Universiti Putra Malaysia, 2010. She was with Institute of Tropical Forestry and Forest Products, UPM as a Post-doctoral fellow and continued her career as a researcher at the Luleå University of Technology (LTU), Lulea, Sweden. She currently works as senior lecturer/research associate at Universiti Putra Malaysia. Her research focused on nanocomposite materials from conducting polymers/biopolymers and their application in sensors, biosensors, and corrosion protection.

The nanocomposite of Polyaniline/ Cellulose nanocrystal (PANI/CNC) was synthesized via in situ chemical polymerization of aniline in the presence of CNC using ammonium peroxydisulfate (APS) as the oxidant. SEM images showed nanostructure of composite with no phase separation revealed homogenous polymerization of monomer in the presence of cellulose nanowhiskers. Aggregation of PANI particles was observed with increasing aniline concentration. The formation of PANI/CNC nanocomposite on SPE electrode followed by the deposition of a thin layer of ion liquid (IL), [BMIM][Cl], film have combined the unique properties of the individual materials and showed synergy effect of CNC/IL on electrocatalytic properties of nanocomposite for electrochemical biosensor application. The higher anodic/cathodi current for PANI/CNC/IL/SPE modified electrode compare to PANI/SPE electrode showed important rule of CNC and IL in accelerating the electron transfer between polymer and the electrode. Application of PANI/CNC nanocomposite modified electrode for cholesterol detection was investigated.

Sonia Yadav has completed her Master’s at University College Dublin, Ireland and Bachelor’s degree at Amity University, India. She is a Bioassay Development Scientist at MiCRA Biodiagnostics (an Enterprise Ireland Technology Gateway). She is currently working on the development & optimization of bioassay methods within a DPTC project for Bacillus cereus spores. Previously, she has worked in the Quality Department of Perfetti Van Melle, where she performed food shelf-life studies and microbial analysis. Her R&D project experience at NEHU involved work on Hsp70 protein, analytical biochemical techniques and immunoassay.

SIGNALMAN is an industrial collaboration between MiCRA Biodiagnostics and the Dairy Processing Technology Centre, a University of Limerick based dairy industry consortium. The project involves the engineering of automated biosensors to detect and enumerate spore-forming bacteria in milk and dairy processing lines. Quality control of processed milk and associated products is of extreme importance to the dairy industry since a variety of micro-organisms is responsible for product quality issues, reduced shelf life and spoilage. Spore-forming bacteria such as Bacillus cereus are identified in milk products by traditional culture and colony counting techniques. These procedures require three days to process samples resulting in serious and costly production delays. It has therefore become essential to develop new technologies to rapidly detect B. cereus during dairy processing. MiCRA Biodiagnostics is involved in the advancement of electronic biochip technology for the rapid detection of B. cereus spores. This biosensor technology relies on immunoassay-ELISA principles and comprises sample-reagent microfluidics and redox-measuring electrodes. The B. cereus BIOCHIP is currently being adapted for biosensor applications in SIGNALMAN.

Younghoon Kim is integrated doctoral course student in Prof. Eunkyoung Kim’s Lab in Yonsei University. His major research area is the application of conducting polymer materials on energy and biomedical applications.

All-organic triboelectric generator (AO-TEG) was explored as a power supplier for a self-powered glucose sensor based on organic electrochemical transistor structure. The AO-TEG showed high voltage (> 700 V), high current density (> 50 mA/m2) and high power density (> 12.9 W/m2) with high stability which comes from the good adhesion of the conducting polymer on dielectric polymer film. Through the management circuit and voltage regulator, the AO-TEG could be demonstrated as a sustainable power source for a glucose sensor. We also introduced the conducting polymer as a glucose sensor using organic electrochemical transistor (OECT) structure. With the redox enzyme glucose oxidase (GOx), glucose was oxidized to the hydrogen peroxide and D-glucono-δ-lactone, and the hydrogen peroxide, subsequently, hydrogen peroxide was oxidized to oxygen and two protons, because of these reaction, the conducting polymer was oxidized, and both the color and the current were significantly changed. These results showed the glucose sensor using the OECT structure could provide dual-detection methods. Futhermore, the detection range and the sensitivity of the sensor could be tuned by adjusting the gate bias. Further analysis on the sensitivity and detection method, and application potential of this method will be discussed in the presentation.

Jongbeom Na is integrated doctoral course student in Prof. Eunkyoung Kim’s Lab in Yonsei University. His major research area is the polymer materials with nanostructure for energy and biomedical applications.

Various protein layers with different thickenss were coated on a conjugated polymer surface and explored for growth and harvesting of cell sheets by NIR photothermal method. There was a large difference in cell morphology among the different protein layers while the dependence of cell growth on the different protein layer was similar to each other. Fibroblasts showed the highest proliferation rate when cultured on the collagaen surface with an optimized thickenss. In this condition, the cell was adhered well indicating that the collagen-coated substrate provides the most favorable surface for cell growth than other substrates. The cells cultured on the protein coated conjugated polymer susbtrate was excited with an NIR laser, to examine the thermal response of the proteins on the polymer substrate. The seggreagtion of protein layers and detachment of cell sheet area were highly dependent on the protein thickness as well as light dose. By adjusting the thickness, concentration, light dose, and polymer layers, a large area cell sheet was spontaneously harvested from the substrate within 5 min of NIR exposure. Further analysis on the proteinsn after NIR exposure, effect of proteins on cell behavior, and application potential of this method will be discussed in the presentaion.

Wonhwi Na is Ph.D student of Department of Micro/Nano system at Korea University. He received his B.Sc. and M.S. in Department of Electrical and Computer Engineering from Sungkyunkwan University. His research efforts include control of microwave based non-contact heating, non-contact temperature measurement, Lab-On-a-Chip, nano material detection, DNA detection, and Surface Plasmon Resonance sensor.

Molecular diagnostics are techniques used to analyze specific biological markers in deoxyribonucleic acid (DNA) sequence. Polymerase Chain Reaction (PCR) is a standard of molecular diagnostics but there are some limitations. First of all, whole processes including PCR and electrophoresis take long time, minimum 3 hours. Also, desktop sized thermal cycler is needed to perform PCR process. Especially, if error is occurred at the initiatory step of PCR, the error is amplified. To solve these problems, in this study, we suggest surface Plasmon resonance (SPR) sensor based direct target DNA detection via gold nanoparticle (AuNP) signal enhancement without DNA amplification. SPR is very sensitive optical sensor suitable for detecting nano sized materials such as protein, DNA, chemicals, etc. However, direct DNA detection from low concentration sample such as patient’s body fluid is impossible. We adopted AuNP for signal enhancement. AuNP DNAs consist of 2 parts, target binding part and receptor binding part, are immobilized on the surfaces of AuNPs. When the target binding part hybridizes with target DNA, Exonuclease III enzyme removes target binding part of AuNP DNA. In this process, target DNAs are not damaged, so other AuNPs with target binding part AuNP DNA can hybridize again and Exonuclease III works. This process makes 1st signal enhancement. The AuNPs have only receptor binding part and captured by receptor DNAs immobilized on sensor chip surface. The captured AuNP enhance the SPR effect, so the detection signal is amplified. Through this method, we successfully amplified SPR signal for direct detect target DNA.

Chun-Lung Lien earned his Master degree in the Department of Photonics of National Chiao Tung University, Hsinchu, Taiwan (ROC). He has over 20 years working experience on working for CMOS analog and digital circuit design. He has been involved and participated in numerous projects mainly in the fields of National sub-micro project, power and high voltage integrated circuits, and optoelectronics. He has also served as a project researcher in the Dynamic Random Access Memory and Static Random Access Memory projects. He has one patent in Taiwan. He is currently a PhD candidate student in the Department of Biological Science and Technology, in National Chiao Tung University, Hsinchu, Taiwan (ROC).

Carbon fiber paper (CFP) has been shown to be suitable a potential electrode materialfor the construction of biosensors due to its low cost, good electrochemical activity and high mechanical resistance. Previously, we have shown that its electrochemical properties can be improved by the oxygen plasma treatment. However, the life time of the enhancing effect of the plasma treatment is short. In this study the effect of metallic nanoparticles modification is explored to improve the enhancing effect of plasma treatmentredox property of CFP. Interestingly, the electrodeposition of palladium nanoparticle (PdNP) on the CFP was found to not only maintain the enhancing effect of plasma treatment, but also increase the electron transfer efficiency of CFP. The electrochemical properties of the electrodeposited Pd nanoparticles were studied and analyzed in terms of their electrochemical responses, electron transfer efficiency, reproducibility and stability. In summary, the electrodeposition of PdNPIt is our hope to establish is an optimal surface modification procedure to improve the electrochemical properties of CFP electrode for future biosensor design and development.

Greter Amelia Ortega Rodríguez has completed her Bachelor of Science in Chemistry (Summa cum Laude) and her Master of Science in Chemistry at University of Havana, Cuba in 2012 and 2015, respectively. At present, she is a graduate teaching assistant at the Department of Inorganic Chemistry, Faculty of Chemistry, University of Havana and a PhD student at Center for Applied Science and Advanced Technology of IPN, Legaria Unit, Mexico. She has participated in 10 international scientific meetings held in Cuba and has done research on synthesis, functionalization and the use of the novel properties of metal and magnetic nanoparticles to design nanostructured biosensors.

Enzyme-linked immunosorbent assays (ELISAs) are the most widely used methods to detect antibodies. However, they have some drawbacks. As a result, in recent years magnetic nanoparticles or beads (e.g. magnetites) have been combined with ELISAs to improve their analytical performance. On the other hand, despite paper-based ELISA are less sensitive than conventional ELISA, they emerge as suitable platforms to develop disposable devices for point-of-care diagnostic. A novel “magnetic-ELISA”, based on core-shell magnetite@polydopamine nanoparticles supported on Whatman paper was developed to detect IgM-dengue antibodies. An affordable procedure to deposit magnetite nanoparticles on paper surfaces (Whatman thype-1 and Whatman thype-ss903) and, to conjugate such nanoparticles with Anti human-IgM antibodies using polydopamine as linker, is reported. Structural features, magnetic behavior, coating homogeneity, as well as, the nanoparticles/linked antibodies ratio were determined. The analytical performance of “magnetic-ELISA” supported on paper surface was 100 times more sensitive with a 700 times lower limit of detection than traditional ELISA or using magnetic beads without depositing on paper to detect IgM-dengue antibodies. Additionally, the new system showed low background, acceptable reproducibility, low-cost, easy manufacturing and effortless and easy handling which are very important, considering the large number of biological samples to be processed by a laboratory in case of dengue epidemics.