October 24, 2019
Gaurav's Goodbye Dinner at Southern Spice, Irvine. From left to right: Valen, Vivian, Anaeis, Annee, Reg, Josh, Ilektra, Unknown Dude in Green Shirt at the Next Table, Nick D., Gaurav, Prof. Won-Kook Choi (KIST), Rayomand, Heriberto, and Nick H. (Missing: Undral, Apurva, and Eric!).

Electrochemical quantification of glycated and non-glycated human serum albumin in synthetic urine
Aisha Attar, Mark Richardson, Gaetano Speciale, Sudipta Majumdar,; Rebekah Dyer, Emily Sanders, Reginald M. Penner*, Gregory Weiss*,

ACS Applied Materials and Interfaces 11 (2019) 4757.

Biomolecular damage caused by elevated serum glucose manifests in the glycation of molecules found in blood. The concentration of glycated molecules provides a direct indication of this damage, and the degree to which normal blood glucose has been elevated, over a specified time period. Aisha and her coworkers devised an elegant electrochemical biosensor able to rapidly and simultaneously measure the concentration of both forms of HSA - glycated and non-glycated. The detection limits she demonstrates exceeds the requirements for intermediate-term glycemic control monitoring in diabetes patients at 5 and 1 nM for albumin and its glycated forms, respectively.

Penner Group BBQ, July 20, 2019. Luna uncooperative, as usual.

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 Csp of 420 mAh/g at 5 A/g and 220 mAh/g at 50 A/g; higher than 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.

July 30, 2019
Meet our NEXTech 2019 nanoscientists with their nanowires (in hand): (from left) Frank Fan (Irvine HS), Emily Dinh (Westminster HS), Eric Bui (Westminster HS), and Rachel Shon (Woodbridge HS).
Congrats to all!

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 3 (2018) 2152.

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).

Gaurav gets hooded!, June 15, 2019. He will join Intel in Hillsboro, Oregon in September.
Congrats Gaurav!!

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 10 (2018) 35344.

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.

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.

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