Niko (left) and Alana with Reg on her graduation day (er, Alana's, that is), last Friday (30 Nov).

Pt-Functionalized PdO Nanowires for Room Temperature Hydrogen Gas Sensors
Hee-Jin Cho, Vivian T. Chen, Shaopeng Qiao, Won-Tae Koo, Reginald M. Penner,* and Il-Doo Kim*

ACS Sensors (2018) Just Accepted.

Hee-Jin prepared arrays of palladium oxide nanowires using LPNE followed by calcination. Platinum nanoparticles were then functionalized on PdO NWs enhancing the detection capability of the Pt-loaded PdO NWs sensors toward H2 at room temperature. Pt NPs activated the dissociation of H2 and oxygen molecules through the spill-over effect, and the subsequent diffusion to the PdO surface, which transformed the entire surface of the PdO NWs into reaction sites for with H2. As a result, the Pt-loaded PdO NWs showed an enhanced sensitivity of 62% compared to that (6.1%) of pristine PdO NWs. The Pt-PdO NWs exhibited a response time of 166 s, which was 2.68-fold faster than that of pristine PdO NWs (445 s).

Electrophoretic Deposition of Mesoporous Niobium(V)Oxide Nanoscopic Films
Gaurav Jha, Thien Tran, Shaopeng Qiao, Joshua M. Ziegler, Alana F. Ogata, Sheng Dai, Mingjie Xu, Mya Le Thai, Girija Thesma Chandran, Xiaoqing Pan*, and Reginald M. Penner*

Chemistry of Materials 30 (2018) 6549.

Gaurav has developed an electrophoretic deposition (ED) process for the synthesis of T-Nb2O5 thin-films. Crystalline, phase pure films of orthorhombic, T-Nb2O5, are obtained by post-deposition calcination. These films exhibit unusually high specific capacities for Li+-based energy storage as a consequence of 70% porosity. For example, a 60 nm thick film displays a specific capacity of 420 mAh/g at 5 A/g and 220 mAh/g at 50 A/g which can be compared with the theoretical Faradaic capacity of 202 mAh/g. T-Nb2O5 films also have a specific energy density in the range from 770 - 486 Wh/kg, and a specific power density in the range from 9-90 kW/kg.

Good-bye to Yong-Jin on October 24 at Umami Burger in Costa Mesa. Clockwise from left: Vivian, Yong-Jin, Reg, Ilektra, Apurva, Eric, Gaurav, and Josh. Missing: Alana, Undral, Ray. Annee.

Rapid, Wet Chemical Fabrication of Radial Junction Electroluminescent Wires
Shaopeng Qiao, Alana F. Ogata, Gaurav Jha, Aurnov Chattopadhyay, and Reginald M. Penner*

ACS Applied Materials and Interfaces (2018) ASAP.

Shaopeng developed a new wet-chemical and electrochemical process - the EESC - for fabricating radial junction LEDs. Hole injection, at a high barrier CdSe-PEDOT:PSS interface, is facilitated by a contact area that is much larger than the complimentary gold-CdSe electron-injecting contact contributing to low voltage thresholds (1.4 - 1.7 V) for EL emission. Au@CdSe@PEDOT:PSS wire EL emitters are 25 microns in length, amongst the longest so far demonstrated to our knowledge, but the EESC process is scalable to nanowires of any length.

Good-bye Lunch for Professor Il-Doo Kim at Eureka! in Irvine, Aug 17, 2018. Clockwise from lower left: Guarav, Undral, Vivian, Prof. Il-Doo, APurva, Annee, Ilektra, Eric, Alana, Reg, and Yong Jin (missing: Josh!).

An Impedance-Transduced Chemiresistor with a Porous Carbon Channel for Rapid, Nonenzymatic, Glucose Sensing
Alana F. Ogata, Seok-Won Song, Su-Ho Cho, Won-Tae Koo, Ji-Soo Jang, Yong Jin Jeong, Min-Hyeok Kim, Jun Young Cheong, Reginald M. Penner*, Il-Doo Kim*

Analytical Chemistry 90 (2018) 9338.

Alana has developed a new type of chemiresistor, the impedance-transduced chemiresistor (ITCR), for the rapid analysis of glucose. The ITCR exploits porous, high surface area, fluorine-doped carbon nanofibers prepared by electrospinning of fluorinated polymer nanofibers followed by pyrolysis. These nanofibers are functionalized with a boronic acid receptor and stabilized by Nafion enabling glucose detection. The recognition and binding of glucose by the ITCR is detected by measuring its electrical impedance at a single frequency.

Good-bye to Su-Ho, and Hello to Yong-Jin on June 29. With (from left) Professor Il-Doo Kim (KAIST), Reg, Su-Ho Cho, and Yong-Jin Jeong, (both of KAIST). The fist symbolizes something at KAIST.

Hierarchical Hierarchical Metal-Organic Framework Assembled Membrane Filter for Efficient Removal of Particulate Matter
Won-Tae Koo, Ji-Soo Jang, Shaopeng Qiao, Wontae Hwang, Gaurav Jha, Reginald M. Penner, and Il-Doo Kim*

ACS Appl Mater Inter 10 (2018) 19957.

Metal-organic frameworks or MOFs can function as efficient particulate filters. The assembly of two-dimensional (2D) Zn-based zeolite imidazole frameworks (2D-ZIF-L) in deionized water over a period of time produced hierarchical ZIF-L (H-ZIF-L) on hydrophilic substrates. Won-Tae and his coworkers demonstrated H-ZIF-L-assembled polypropylene microfibers as a washable membrane filter with highly efficient PM removal property (92.5 +/- 0.8% for PM2.5 and 99.5 +/- 0.2% for PM10), low pressure drop (10.5 Pa at 25 L/min), long-term stability, and superior recyclability. These outstanding particle filtering properties are mainly attributed to the unique structure of the 2D-shaped H-ZIF-L, which is tightly anchored on individual fibers comprising the membrane.

The Virus BioResistor: Wiring Virus Particles for the Direct, Label-Free Detection of Target Proteins
Apurva Bhasin, Alana F. Ogata, Jeffrey S. Briggs, Phillip Y. Tam, Ming X. Tan, Gregory A. Weiss*, Reginald M. Penner*
Nano Letters 18 (2018) 3623.

As co-first authors, Apurva and Alana have invented the virus bioresistor (VBR) which is a chemiresistor that directly transfers information from virus particles to an electrical circuit. Specifically, the VBR enables the label-free detection of a target protein that is recognized and bound by filamentous M13 virus particles, each with dimensions of 6 nm (w) x 1 micron (l), entrained in an ultrathin (250 nm) composite virus - polymer resistor. The VBR concept is demonstrated using a model system in which human serum albumin (HSA, 66 kDa) is detected in a phosphate buffer solution. The resistance change induced by HSA binding is as high as 200 Ohms, contributing to low sensor-to-sensor coefficients-of-variation (<15%) across the entire calibration curve for HSA from 7.5 nM to 900 nM. The response time for the VBR is 3 - 30 s.

Friday, March 2, 2018
Alana (at right) wins the UCI GradSlam! with her talk, ``The Future of Early Detection: An at Home Cancer Test'' Now, it's on to the UC-Wide Grad-Slam competition on May 3! Congrats Alana!! (photo credit: Gaurav Jha).

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