1 August 2018
IME’s research achievements have recently received much attention from top notch journals. The papers titled “DNA Sensing by Silicon Nanowire: Charge Layer Distance Dependence” and “Palm-Sized Biodetection System Based on Localized Surface Plasmon Resonance” were highlighted in Nano Letters. 8, 1066-1070 (2008) and ASAP Analytical Chemical, ASAP Article, 10.1021/ac800335q respectively. The publications were well-received and attained further writings in several journals.
DNA Sensing by Silicon Nanowire: Charge Layer Distance Dependence
Guo-Jun Zhang, Gang Zhang, Jay Huiyi Chua, Ru-Ern Chee, Ee Hua Wong, Ajay Agarwal, Kavitha D. Buddharaju, Navab Singh, Zhiqiang Gao, and N. Balasubramanian
The study provides a comprehensive understanding of the field effect in silicon nanowire (SiNW) sensors by taking a systematic approach to fine tune the distance of a charge layer by controlling the hybridization sites of DNA to the SiNW functionalized with peptide nucleic acid (PNA) capture probes. To do this, six target DNA oligonucleotide sequences of the same length, but differing in three base pairs in the complementary segment, were successfully hybridized onto the PNA molecule. It is found that the field-effect response of the SiNW sensor depends on the distance between the charges inherent in the DNA molecule and the silicon surface, indicated by the decrease in sensor response as the charge layer moves further away from the silicon surface. Theoretical analysis further verifies that the field effect of the SiNW sensor relies primarily on the location of the charge layer. This work helps understand the fundamental issues on the detection sensitivity in the SiNW biosensors.
Reported in American Chemical Society - DNA Sensing by Silicon Nanowire: Charge Layer Distance Dependence; NPG Asia Materials - Nanowires and DNA: Get closer.
Palm-Sized Biodetection System Based on Localized Surface Plasmon Resonance
Pavel Neuzil and Julien Reboud
IME researchers presented a biodetection system based on highly sensitive localized surface plasmon resonance (LSPR) by replacing the spectrum analyzer by four pulse-powered light-emitting diodes (LED), each with different emission spectra. A single photodiode was used to detect the reflected light beams from the LEDs and its composite output current was demultiplexed by a four-channel lock-in amplifier. The device performance was demonstrated using an LSPR chip covered with a mixture of ethanol/water and 2-propanol/water at different concentrations. The miniaturized system is palm-sized and battery-operated, making it suitable for point-of-care and field applications.
Reported in American Chemical Society - Palm-Sized Biodetection System Based on Localized Surface Plasmon Resonance; Science Daily - New Generation of Simpler Sensors For Detecting Disease-causing Microbes and Toxins; LAB.medinews.com - Palm-Sized Sensor Detects Disease-Causing Microbes; Medical News TODAY - A New-Generation of Simpler Sensors for Detecting Disease-Causing Microbes and Toxins and Nanowerk.com - A New-Generation of Simpler Sensors for Detecting Disease-Causing Microbes and Toxins.