Suppression of Coffee-Ring Effect on Nitrocellulose Membrane: Effect of Polyethylene Glycol

• Published in: Pertanika Journal of Science and Technology
• Main Author: Shahruddin S.S.; Ideris N.; Kamarulzaman N.A.
• Format: Article
• Language: English
• Published: Universiti Putra Malaysia Press 2022
• Online Access: https://www.scopus.com/inward/record.uri?eid=2-s2.0-85139237920&doi=10.47836%2fpjst.30.4.20&partnerID=40&md5=f047a33dd90732c127e529ac07dc2b83

In the development of the diagnostic kit, it was favorable to have a low antigen concentration due to the difficulty of antigen preparedness and purification. However, it can cause the coffee-ring effect, producing different pattern formations on the selected membrane. It can lead to a false interpretation of the result. Thus, the immobilization of protein solution (lysozyme) as a model protein for antigen, with the addition of hydrosoluble polymer additive onto a membrane, was evaluated to suppress the coffee-ring effect. This research aims to evaluate the effect of polyethylene glycol on the protein solution for coffee-ring effect suppression and to analyze the image of the coffee-ring effect. From the experimental studies, 5 different concentrations (v/v%) of PEG which are 3.0, 2.0, 1.0, 0.1 and 0.01 v/v% is added at 4.0 mg/mL of lysozyme solution before being spotted onto nitrocellulose membrane. The color intensity of the dried spot, together with the formation of the coffee-ring effect, is analyzed by Image-J software. It is the approach to measure the suppression of the ring effect, in which 0.01 v/v% concentration portrays the most faded ring effect on nitrocellulose membrane. This effect occurs due to a surface tension gradient that causes the solute particles to accumulate at the edge of the droplet. As Marangoni flow has been altered, the coffee-ring effect is successfully suppressed; thus, uniform pattern deposition is achieved. © Universiti Putra Malaysia Press.