APL: Applied Biophysics http://scitation.aip.org/ APL: Applied Biophysics All-silicon integrated FabryPerot cavity for volume refractive index measurement in microfluidic systems http://link.aip.org/link/?APL/94/243905/1&agg=rss R. St-Gelais, J. Masson, and Y.-A. Peter<br/> We report a refractive index (RI) sensor based on the use of vertically etched silicon Bragg reflectors. The device is robust and performs measurements through tens of micrometers of liquid. A sensitivity of 907 nm/RIU (RI units) and a resolution of 1.7 x 10 RIU are obtained and are in good agreeme ... [Appl. Phys. Lett. 94, 243905 (2009)] published Tue Jun 16, 2009. A biomolecular detection method based on charge pumping in a nanogap embedded field-effect-transistor biosensor http://link.aip.org/link/?APL/94/243903/1&agg=rss Sungho Kim, Jae-Hyuk Ahn, Tae Jung Park, Sang Yup Lee, and Yang-Kyu Choi<br/> A unique direct electrical detection method of biomolecules, charge pumping, was demonstrated using a nanogap embedded field-effect-transistor (FET). With aid of a charge pumping method, sensitivity can fall below the 1 ng/ml concentration regime in antigen-antibody binding of an avian influenza cas ... [Appl. Phys. Lett. 94, 243903 (2009)] published Tue Jun 16, 2009. Acoustic detection of microbubble resonance http://link.aip.org/link/?APL/94/243902/1&agg=rss D. H. Thomas, P. Looney, R. Steel, N. Pelekasis, W. N. McDicken et al.<br/> Large numbers of acoustic signals from single lipid-shelled Definity[registered sign] microbubbles have been measured using a calibrated microacoustic system and a two population response observed. Theoretical results based on the MooneyRivlin strain softening shell model have been used to identify ... [Appl. Phys. Lett. 94, 243902 (2009)] published Tue Jun 16, 2009. Self-formation of bilayer lipid membranes on agarose-coated silicon surfaces studied by simultaneous electrophysiological and surface infrared spectroscopic measurements http://link.aip.org/link/?APL/94/243906/1&agg=rss Ayumi Hirano-Iwata, Azusa Oshima, Kota Onodera, Kouji Aoto, Tasuku Taira et al.<br/> Self-formation process of bilayer lipid membranes (BLMs) cushioned on agarose-coated Si surfaces was in situ monitored by simultaneous electrophysiological and infrared absorption spectroscopic (IRAS) measurements using IRAS with the multiple internal reflection geometry. IRAS signals corresponding ... [Appl. Phys. Lett. 94, 243906 (2009)] published Tue Jun 16, 2009. Microscale structural model of Alzheimer Abeta(140) amyloid fibril http://link.aip.org/link/?APL/94/243904/1&agg=rss Raffaella Paparcone and Markus J. Buehler<br/> Amyloid fibril formation and characterization are crucial due to their association with severe degenerative disorders such as Alzheimer's, type II diabetes, and Parkinson's disease. Here we present an atomistic-based multiscale analysis, utilized to predict the structure of Alzheimer Abeta(140) fibr ... [Appl. Phys. Lett. 94, 243904 (2009)] published Tue Jun 16, 2009. Fast detection of a protozoan pathogen, Perkinsus marinus, using AlGaN/GaN high electron mobility transistors http://link.aip.org/link/?APL/94/243901/1&agg=rss Yu-Lin Wang, B. H. Chu, K. H. Chen, C. Y. Chang, T. P. Lele et al.<br/> Antibody-functionalized, Au-gated AlGaN/GaN high electron mobility transistors (HEMTs) were used to detect Perkinsus marinus. The antibody was anchored to the gate area through immobilized thioglycolic acid. The AlGaN/GaN HEMT drain-source current showed a rapid response of less than 5 s when the in ... [Appl. Phys. Lett. 94, 243901 (2009)] published Tue Jun 16, 2009. Facile biosynthesis of phosphate capped gold nanoparticles by a bacterial isolate Stenotrophomonas maltophilia http://link.aip.org/link/?APL/94/233901/1&agg=rss Yogesh Nangia, Nishima Wangoo, Saurabh Sharma, Jin-Song Wu, Vinayak Dravid et al.<br/> We report intracellular biosynthesis of gold nanoparticles (GNPs) by a strain Stenotrophomonas maltophilia (AuRed02) isolated from the soil samples of Singhbhum gold mines, India. An aqueous solution of gold chloride was reduced to metallic gold in a suspension of disrupted cell mass of AuRed02, whi ... [Appl. Phys. Lett. 94, 233901 (2009)] published Mon Jun 8, 2009. Quantifying thermodynamics of collagen thermal denaturation by second harmonic generation imaging http://link.aip.org/link/?APL/94/233902/1&agg=rss Vladimir A. Hovhannisyan, Ping-Jung Su, Sung-Jan Lin, and Chen-Yuan Dong<br/> Time-lapse second harmonic generation (SHG) microscopy was applied for the extraction of thermodynamic parameters of collagen thermal denaturation. We found that at sufficiently high temperatures, temporal dependence of SHG intensity from the isothermal treatment of chicken dermal collagen was singl ... [Appl. Phys. Lett. 94, 233902 (2009)] published Mon Jun 8, 2009. Second harmonic generation chi tensor microscopy for tissue imaging http://link.aip.org/link/?APL/94/183902/1&agg=rss Wei-Liang Chen<!--orlang--> (&#x9673;&#x7DAD;&#x826F;)<!--orlang-->, Tsung-Hsian Li<!--orlang--> (&#x674E;&#x5B97;&#x61B2;)<!--orlang-->, Ping-Jung Su<!--orlang--> (&#x8607;&#x79C9;&#x69AE;)<!--orlang-->, Chen-Kuan Chou<!--orlang--> (&#x5468;&#x653F;&#x5BEC;)<!--orlang-->, Peter Tramyeon Fwu<!--orlang--> (&#x7B26;&#x50B3;&#x52C7;)<!--orlang--> et al.<br/> Important biological molecules such as collagen and myosin are strong second harmonic generators. The polarization dependence of second-harmonic generation (SHG) is a property of the second order susceptibility elements (chi tensor) of the molecules that produce the signal. In this work, we used pol ... [Appl. Phys. Lett. 94, 183902 (2009)] published Fri May 8, 2009. Electrical transport through ordered self-assembled protein monolayer measured by constant force conductive atomic force microscopy http://link.aip.org/link/?APL/94/183901/1&agg=rss Jani M. Kivioja, Katri Kurppa, Markku Kainlauri, Markus B. Linder, and Jouni Ahopelto<br/> This paper addresses some of the challenges met in electrical characterization of biomolecules, namely, the control of the orientation of molecules and the control of the force exerted on these soft molecules. We investigate the transport properties of small proteins called hydrophobins using conduc ... [Appl. Phys. Lett. 94, 183901 (2009)] published Thu May 7, 2009. Separation of beta-human chorionic gonadotropin and immunoglobulin G by a miniaturized size exclusion chromatography column http://link.aip.org/link/?APL/94/173902/1&agg=rss Yongmo Yang and Junseok Chae<br/> This report describes a miniaturized size exclusion chromatography column that effectively preseparates raw samples for medical point-of-care testing (POCT) devices. The minicolumn is constructed of polydimethylsiloxane fabricated on a glass slide. The minicolumn separates 300 ng/ml of beta-human ch ... [Appl. Phys. Lett. 94, 173902 (2009)] published Fri May 1, 2009. Time-reversal focusing of therapeutic ultrasound on targeted microbubbles http://link.aip.org/link/?APL/94/173901/1&agg=rss Olivier Couture, Jean-Francois Aubry, Mickael Tanter, and Mathias Fink<br/> Targeted microbubbles bind specifically to molecular markers of diseases and their unique acoustic signature is used to image cellular processes in vivo. The ability of time-reversal processing to focus waves through heterogeneities on such targeted microbubbles is demonstrated. For this purpose, mi ... [Appl. Phys. Lett. 94, 173901 (2009)] published Mon Apr 27, 2009. Mechanics of membrane instability in biological cells http://link.aip.org/link/?APL/94/163903/1&agg=rss Yong-Wei Zhang<br/> A model is presented to show that the cell membrane supported by viscoelastic cytoplasm and driven by the periodic actions of the extensile force due to actin assembly and the contractile force due to myosin complex can create periodical mechanical instabilities, leading to giant periodic membrane l ... [Appl. Phys. Lett. 94, 163903 (2009)] published Fri Apr 24, 2009. Superhydrophobic cellulose-based bionanocomposite films from Pickering emulsions http://link.aip.org/link/?APL/94/163902/1&agg=rss Ilker S. Bayer, Adam Steele, Philip J. Martorana, Eric Loth, and Lance Miller<br/> Inherently superhydrophobic and flexible cellulose-based bionanocomposites were fabricated from solid stabilized (Pickering) emulsions. Emulsions were formed by dispersing cyclosiloxanes in water stabilized by layered silicate particles and were subsequently modified by blending into a zinc oxide na ... [Appl. Phys. Lett. 94, 163902 (2009)] published Wed Apr 22, 2009. Galvanotactic and phototactic control of Tetrahymena pyriformis as a microfluidic workhorse http://link.aip.org/link/?APL/94/163901/1&agg=rss Dal Hyung Kim, David Casale, Laszlo K&#x0151;hidai, and Min Jun Kim<br/> A eukaryotic ciliate, Tetrahymena pyriformis, has been controlled using galvanotaxis and phototaxis in a low Reynolds number fluidic environment. A cell-tracking algorithm demonstrates the controllability of Tetrahymena pyriformis under two types of external stimuli. Electrical stimulation, in the f ... [Appl. Phys. Lett. 94, 163901 (2009)] published Mon Apr 20, 2009. Evidence of elastic to plastic transition in the zona pellucida of oocytes using atomic force spectroscopy http://link.aip.org/link/?APL/94/153902/1&agg=rss Massimiliano Papi, Lakamy Sylla, Tiziana Parasassi, Roberto Brunelli, Maurizio Monaci et al.<br/> We have investigated the mechanical properties of the zona pellucida (ZP), a multilayer glycoprotein coat that surrounds mammalian eggs, using atomic force spectroscopy. The response of the membrane to mechanical stress has been reconstructed using a modified Hertz model. The transition from elastic ... [Appl. Phys. Lett. 94, 153902 (2009)] published Thu Apr 16, 2009. Magnetic bead counter using a micro-Hall sensor for biological applications http://link.aip.org/link/?APL/94/153903/1&agg=rss Wonhyun Lee, Sungjung Joo, Sun Ung Kim, Kungwon Rhie, Jinki Hong et al.<br/> Micro-Hall sensors have been fabricated, and various numbers of micron-size magnetic beads have been placed within the sensor area. The Hall resistances measured at room temperature are found to be proportional to the number of the beads, and are in good agreement with the numerically simulated resu ... [Appl. Phys. Lett. 94, 153903 (2009)] published Thu Apr 16, 2009. Effect of hydration on the structure of caveolae membranes http://link.aip.org/link/?APL/94/153901/1&agg=rss Giulio Caracciolo, Fabio Sciubba, and Ruggero Caminiti<br/> In situ energy dispersive x-ray diffraction was used to investigate the effect of hydration on the structure of caveolae membranes. The structure of caveolae membrane was found to be strongly dependent on hydration. At low hydration two lamellar phases with distinct repeat spacings were found to coe ... [Appl. Phys. Lett. 94, 153901 (2009)] published Mon Apr 13, 2009. DNA-quantum dot sensing platform with combined Forster resonance energy transfer and photovoltaic effect http://link.aip.org/link/?APL/94/143902/1&agg=rss Huijie Qi, Lixiang Wang, Ka-wai Wong, and Zuliang Du<br/> A special DNA sensing platform based on a network of hybrid DNA-quantum dot system was designed and fabricated. Upon attachment of hybridized complementary DNA sequences, the molecular switch system can exhibit both photoinduced Forster resonance energy transfer (FRET) and photovoltaic (PV) effects ... [Appl. Phys. Lett. 94, 143902 (2009)] published Fri Apr 10, 2009. Nanostructured zinc oxide platform for cholesterol sensor http://link.aip.org/link/?APL/94/143901/1&agg=rss Pratima R. Solanki, Ajeet Kaushik, Anees A. Ansari, and B. D. Malhotra<br/> Nanostructured zinc oxide (nano-ZnO) film has been fabricated onto indium tin oxide (ITO) containing preferred (002) plane and 10 nm crystallite size using sol-gel technique for immobilization of cholesterol oxidase (ChOx). Electrochemical response of ChOx/nano-ZnO/ITO bioelectrode determined as a f ... [Appl. Phys. Lett. 94, 143901 (2009)] published Wed Apr 8, 2009. Light driven microflow in ice http://link.aip.org/link/?APL/94/113901/1&agg=rss Franz M. Weinert, Max Wuhr, and Dieter Braun<br/> We optically pump water through micrometer thin ice sheets. The ice is locally moved with speeds exceeding 5 cm/s by repetitive melting and freezing, which occurs around a moving infrared laser spot. The minimal channel width is 10 [mu]m. The diffusion limitation of ice allows for fast spatial biom ... [Appl. Phys. Lett. 94, 113901 (2009)] published Mon Mar 16, 2009.