Nunna Bharath Babu, Mandal Debdyuti, Lee Joo Un, Singh Harsimranjit, Zhuang Shiqiang, Misra Durgamadhab, Bhuyian Md Nasir Uddin, Lee Eon Soo
Advanced Energy Systems and Microdevices Laboratory, Department of Mechanical and Industrial Engineering, New Jersey Institute of Technology, 200 Central Avenue, Rm MEC 327, Newark, NJ, 07102-1982, USA.
Provost Summer Research Intern at New Jersey Institute of Technology & Tenafly High School, Tenafly, NJ, USA.
Nano Converg. 2019 Jan 17;6(1):3. doi: 10.1186/s40580-019-0173-6.
Integrating microfluidics with biosensors is of great research interest with the increasing trend of lab-on-the chip and point-of-care devices. Though there have been numerous studies performed relating microfluidics to the biosensing mechanisms, the study of the sensitivity variation due to microfluidic flow is very much limited. In this paper, the sensitivity of interdigitated electrodes was evaluated at the static drop condition and the microfluidic flow condition. In addition, this study demonstrates the use of gold nanoparticles to enhance the sensor signal response and provides experimental results of the capacitance difference during cancer antigen-125 (CA-125) antigen-antibody conjugation at multiple concentrations of CA-125 antigens. The experimental results also provide evidence of disease-specific detection of CA-125 antigen at multiple concentrations with the increase in capacitive signal response proportional to the concentration of the CA-125 antigens. The capacitive signal response of antigen-antibody conjugation on interdigitate electrodes has been enhanced by approximately 2.8 times (from 260.80 to 736.33 pF at 20 kHz frequency) in static drop condition and approximately 2.5 times (from 205.85 to 518.48 pF at 20 kHz frequency) in microfluidic flow condition with gold nanoparticle-coating. The capacitive signal response is observed to decrease at microfluidic flow condition at both plain interdigitated electrodes (from 260.80 to 205.85 pF at 20 kHz frequency) and gold nano particle coated interdigitated electrodes (from 736.33 to 518.48 pF at 20 kHz frequency), due to the strong shear effect compared to static drop condition. However, the microfluidic channel in the biosensor has the potential to increase the signal to noise ratio due to plasma separation from the whole blood and lead to the increase concentration of the biomarkers in the blood volume for sensing.
随着芯片实验室和即时检测设备的不断发展,将微流控技术与生物传感器相结合成为了一个备受关注的研究领域。虽然已经有许多关于微流控技术与生物传感机制相关的研究,但关于微流控流动引起的灵敏度变化的研究却非常有限。在本文中,我们评估了叉指电极在静态液滴条件和微流控流动条件下的灵敏度。此外,本研究展示了使用金纳米颗粒来增强传感器信号响应,并提供了在多种浓度的癌抗原125(CA - 125)抗原 - 抗体结合过程中的电容差实验结果。实验结果还证明了在多种浓度下对CA - 125抗原进行疾病特异性检测的可能性,电容信号响应随着CA - 125抗原浓度的增加而增加。在静态液滴条件下,叉指电极上抗原 - 抗体结合的电容信号响应通过金纳米颗粒涂层增强了约2.8倍(在20 kHz频率下从260.80 pF增加到736.33 pF),在微流控流动条件下增强了约2.5倍(在20 kHz频率下从205.85 pF增加到518.48 pF)。在微流控流动条件下,无论是普通叉指电极(在20 kHz频率下从260.80 pF降至205.85 pF)还是金纳米颗粒涂层叉指电极(在20 kHz频率下从736.33 pF降至518.48 pF),电容信号响应都有所下降,这是由于与静态液滴条件相比,剪切效应更强。然而,生物传感器中的微流控通道有可能通过从全血中分离血浆来提高信噪比,并导致用于传感的血样中生物标志物浓度增加。