A capillary driven microfluidic chip for SERS based hCG detection

Ahi, Elcin Ezgi
Zengin, Adem
Sucularli, Ferah
Yıldırım, Ender
Selbes, Yesim
In this study, a capillary driven microfluidic chip-based immunoassay was developed for the determination of Human Chorionic Gonadotropin (hCG) protein, which is prohibited by the World Anti-Doping Agency (WADA). Here, we used antibody modified magnetic metal organic framework nanoparticles (MMOFs) as a capture prob in urine sample. MMOF captured hCG was transferred in a capillary driven microfluidic chip consisting of four chambers, and the interaction of MMOF with gold nanorods labelled with 5,5'-Dithiobis-(2-nitrobenzoic acid) (DTNB) as a Raman label was carried out in the capillary driven microfluidic chip. The movement of MMOF through first chamber to the last chamber was achieved with a simple magnet. In the last chamber of capillary driven microfluidic chip, SERS signals of DTNB molecules from the sandwich complex were recorded using a Raman spectrophotometer. The selectivity of the developed method was demonstrated by applying the same procedure for the detection of Human Luteinizing Hormone (hLH), Human Chorionic Gonadotropin Hormone (hGH) and Immunoglobulin G (IgG) protein. The regression coefficient and limit of detection obtained from the standard addition method were found as 0,9985 and 0,61 IU/L, respectively. Furthermore, the conventional ELISA method confirmed that the results obtained by the presented method were acceptable with the similarity of 97.9% in terms of average recovery value, for the detection of hCG in urine samples. The analysis system developed for target proteins will be an alternative technique such as Western Blot used in routine analysis that is expensive and time consuming.


A novel architecture based on a conducting polymer and calixarene derivative: its synthesis and biosensor construction
GOKOGLAN, Tugba Ceren; SOYLEMEZ, Saniye; KESIK, Melis; UNAY, Hande; Sayin, Serkan; Yildiz, Huseyin Bekir; Çırpan, Ali; Toppare, Levent Kamil (2015-01-01)
In this study, a novel amperometric glucose biosensor based on a selenium comprising conducting polymer and calixarene was developed. Firstly, poly(2-(2-octyldodecyl)-4,7-di(selenoph-2-yl)-2H-benzo[d][1,2,3]-triazole), poly((SBTz)) was electrodeposited onto a graphite electrode by an electropolymerization technique. Then, a newly synthesized calixarene and gold nanoparticle (AuNP) mixture was used for the improvement of biosensor characteristics. GOx, as a model enzyme was immobilized on the modified electr...
Defined and complex medium based feeding strategy development for recombinant human growth hormone production by P. pastoris under GAP promoter
Hoxha, Bebeta; Çalık, Pınar; Özdamar, Tunçer H.; Department of Chemical Engineering (2016)
The objective of this study is to investigate different feeding strategies leading to higher recombinant human growth hormone (rhGH) production by Pichia pastoris, driven under constitutive promoter of the glyceraldehyde-3-phosphate dehydrogenase gene. rhGH production took place in a pilot bioreactor where glucose and molasses were examined as carbon sources. For batch phase, which is the first production phase of the reactor, all experiments share the same characteristics where glycerol was utilized as the...
A Novel Artificial Pancreas: Energy Efficient Valveless Piezoelectric Actuated Closed-Loop Insulin Pump for T1DM
Kacar, Alp; Özer, Mehmet Bülent; Tascioglu, Yigit (2020-08-01)
The objective of this work is to develop a closed-loop controlled insulin pump to keep the blood glucose level of Type 1 diabetes mellitus (T1DM) patients in the desired range. In contrast to the existing artificial pancreas systems with syringe pumps, an energy-efficient, valveless piezoelectric pump is designed and simulated with different types of controllers and glucose-insulin models. COMSOL Multiphysics is used for piezoelectric-fluid-structural coupled 3D finite element simulations of the pump. Then,...
A high-throughput microfluidic rare cell enrichment system based on dielectrophoresis and filtering
Ozkayar, Gurhan; Yalcin, Yagmur Demircan; Ozgur, Ebru; Gündüz, Ufuk; Külah, Haluk (2016-05-27)
In this study, a MEMS-based microfluidic device combining DEP-based cell manipulation with size-based filtration for the enrichment of CTCs from blood with high-throughput was developed. Positive-DEP (pDEP) force and the hydrodynamic force have been used to fine-tune the cell movement over the planar electrodes (sliding) at a high flow rate (30 mu l/min). While smaller sized RBCs passed through the gaps and were directed to the waste channels, cancer cells (K562 cells) were filtered and directed to the canc...
A non-conventional TD-NMR approach to monitor honey crystallization and melting
Berk, Berkay; Grunin, Leonid; Öztop, Halil Mecit (Elsevier BV, 2021-03-01)
© 2020 Elsevier LtdCrystallization of glucose is a natural process that could occur in honey due to several reasons and glucose is one of them. In this study, a non-conventional TD-NMR pulse sequence, Magic Sandwich Echo (MSE), was used to monitor the crystallization of honey at 14 °C. Honey samples were seeded with glucose to induce crystallization. T1 and T2 relaxation times were also measured during 96 h of storage. Mono-exponential and bi-exponential relations were used to explain T1 and T2, respectivel...
Citation Formats
E. E. Ahi et al., “A capillary driven microfluidic chip for SERS based hCG detection,” BIOSENSORS & BIOELECTRONICS, vol. 195, pp. 0–0, 2022, Accessed: 00, 2022. [Online]. Available: https://hdl.handle.net/11511/95142.