Bioengineering / Biyomühendislik
Permanent URI for this collectionhttps://hdl.handle.net/11147/4529
Browse
2 results
Search Results
Article Citation - WoS: 11Citation - Scopus: 11Absorbance-Based Detection of Arsenic in a Microfluidic System With Push-And Pumping(Elsevier, 2021) Karakuzu, Betül; Gülmez, Yekta; Tekin, H. CumhurRapid and portable analysis of arsenic (As) contamination in drinking water is very important due to its adverse health effects on humans. Available commercial detection kits have shown low sensitivity and selectivity in analysis, and also they can generate harmful by-products. Microfluidic-based approaches allow portable analysis with gold nanoparticles (AuNPs) as labels. However, they need complex surface modification steps that complicate detection protocols. Due to the lack of precise sensing and affordable solution, we focused on developing a microfluidic platform that uses a push-and-pull pumping method for sensitive detection of As. In this detection principle, a sample is introduced in the microfluidic channel modified with -SH functional groups where As can bind. Then, AuNPs are given in the channel and AuNPs bind on free -SH functional groups which are not allocated with As. Absorbance measurements are conducted to detect AuNPs absorbed on the surfaces and the resulting absorbance value is inversely proportional with As concentration. The method enables detection of As down to 2.2 mu g/L concentration levels in drinking water, which is well-below the allowed maximum As concentration of 10 mu g/L in the drinking waters by the World Health Organization (WHO). The paper reveals that multiple push-and-pull pumping of fixed volume of sample and AuNPs with a syringe pump can improve the binding efficiency in the microfluidic channel. With this technique, low amounts of sample (1 mL) and short total assay time (25 min) are sufficient to detect As.Conference Object Immobilized Gold Nanoparticle Based Plasmonic Assay Platform for Biomolecule and Microorganism Detection(Wiley, 2021) Sözmen, Alper Baran; Arslan Yıldız, AhuPlasmonic sensors are suitable tools for study of molecular interactions. Localized Surface Plasmon Resonance (LSPR) based sensors detect spectral changes associated with intramolecular interactions between analyte molecules and recognition elements. Due to its labelfree and highly sensitive features, LSPR based methods have high potential for biosensing applications. In this study, we aim to develop a sensitive, labelfree, rapid and simple biosensing platform. For this purpose, a novel refractive index (RI) sensitivity enhancement methodology is proposed by immobilizing gold nanoparticles (GNPs) for platformbased LSPR. Fabrication of platform was carried out by GNP synthesis, immobilization of GNPs on polystyrene solid support, and growth of GNPs. Validation of response to RI changes of developed sensor platform was carried out by tests with varying concentrations of sucrose and ethanol. Then as a proofofconcept, detection ability and detection limit determination of E.coli BL21 (DE3) and protein Bovine Serum Albumin (BSA) was carried out. Adsorption of E.coli BL21 (DE3) via bulk interactions showed that the developed LSPR platform exhibit high enough binding affinity for bacteria detection, and was able to detect down to concentrations as low as 102 CFU/ml. Immune capturing of BSA via antiBSA antibody showed that the developed LSPR platform was able to detect BSA protein–antibody interaction down to 10 µM concentration range.