PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

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.

• Ahmad, A. L., Ideris, N., Ooi, B. S., Low, S. C., & Ismail, A. (2016a). Impact of membrane pore structure on protein detection sensitivity of affinity-based immunoassay. Polish Journal of Chemical Technology, 18(2), 97-103. https://doi.org/10.1515/pjct-2016-0035

• Ahmad, A. L., Ideris, N., Ooi, B. S., Low, S. C., & Ismail, A. (2016b). Optimization of polyvinylidene fluoride (PVDF) membrane fabrication for protein binding using statistical experimental design. Journal of Immunoassay and Immunochemistry, 37(4), 421-437. https://doi.org/10.1080/15321819.2016.1157489

• Bansal, L., Seth, P., Murugappan, B., & Basu, S. (2018). Suppression of coffee ring: (Particle) size matters. Applied Physics Letters, 112(21), Article 211605. https://doi.org/10.1063/1.5034119

• Cao, B. H., & Kim, M. W. (1994). Molecular weight dependence of the surface tension of aqueous poly(ethylene oxide) solutions. Faraday Discussions, 98, 245-252. https://doi.org/10.1039/FD9949800245

• Carreón, Y. J. P., Ríos-Ramírez, M., Vázquez-Vergara, P., Salinas-Almaguer, S., Cipriano-Urbano, I., Briones-Aranda, A., Díaz-Hernández, O., Santos, G. J. E., & González-Gutiérrez, J. (2021). Effects of substrate temperature on patterns produced by dried droplets of proteins. Colloids and Surfaces B: Biointerfaces, 203, Article 111763. https://doi.org/10.1016/j.colsurfb.2021.111763

• Cui, L., Zhang, J., Zhang, X., Huang, L., Wang, Z., Li, Y., Gao, H., Zhu, S., Wang, T., & Yang, B. (2012). Suppression of the coffee ring effect by hydrosoluble polymer additives. ACS Applied Materials and Interfaces, 4(5), 2775-2780. https://doi.org/10.1021/am300423p

• Devineau, S., Anyfantakis, M., Marichal, L., Kiger, L., Morel, M., Rudiuk, S., & Baigl, D. (2016). Protein adsorption and reorganization on nanoparticles probed by the coffee-ring effect: Application to single point mutation detection. Journal of the American Chemical Society, 138(36), 11623-11632. https://doi.org/10.1021/jacs.6b04833

• Du, P., Zhao, J., Mashayekhi, H., & Xing, B. (2014). Adsorption of bovine serum albumin and lysozyme on functionalized carbon nanotubes. Journal of Physical Chemistry C, 118(38), 22249-22257. https://doi.org/10.1021/jp5044943

• Eral, H. B., Augustine, D. M., Duits, M. H. G., & Mugele, F. (2011). Suppressing the coffee stain effect: How to control colloidal self-assembly in evaporating drops using electrowetting. Soft Matter, 7(10), 4954-4958. https://doi.org/10.1039/c1sm05183k

• Hu, Y. C., Zhou, Q., Ye, H. M., Wang, Y. F., & Cui, L. S. (2013). Peculiar surface profile of poly(ethylene oxide) film with ring-like nucleation distribution induced by Marangoni flow effect. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 428, 39-46. https://doi.org/10.1016/j.colsurfa.2013.03.035

• Kurien, B. T., & Scofield, R. H. (2015). Detection of blotted proteins: Methods and protocols. Detection of Blotted Proteins: Methods and Protocols, 1314, 1-386. https://doi.org/10.1007/978-1-4939-2718-0

• Majumder, M., Rendall, C. S., Eukel, J. A., Wang, J. Y. L., Behabtu, N., Pint, C. L., Liu, T. Y., Orbaek, A. W., Mirri, F., Nam, J., Barron, A. R., Hauge, R. H., Schmidt, H. K., & Pasquali, M. (2012). Overcoming the “coffee-stain” effect by compositional marangoni-flow-assisted drop-drying. Journal of Physical Chemistry B, 116(22), 6536-6542. https://doi.org/10.1021/jp3009628

• Mampallil, D., Reboud, J., Wilson, R., Wylie, D., Klug, D. R., & Cooper, J. M. (2015). Acoustic suppression of the coffee-ring effect. Soft Matter, 11(36), 7207-7213. https://doi.org/10.1039/c5sm01196e

• Marin, A., Liepelt, R., Rossi, M., & Kähler, C. J. (2016). Surfactant-driven flow transitions in evaporating droplets. Soft Matter, 12(5), 1593-1600. https://doi.org/10.1039/c5sm02354h

• Nilghaz, A., Zhang, L., & Shen, W. (2015). Coffee stains on paper. Chemical Engineering Science, 129, 34-41. https://doi.org/10.1016/j.ces.2015.02.017

• Nowak, E., Kovalchuk, N. M., Che, Z., & Simmons, M. J. H. (2016). Effect of surfactant concentration and viscosity of outer phase during the coalescence of a surfactant-laden drop with a surfactant-free drop. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 505, 124-131. https://doi.org/10.1016/J.COLSURFA.2016.02.016

• Seo, C., Jang, D., Chae, J., & Shin, S. (2017). Altering the coffee-ring effect by adding a surfactant-like viscous polymer solution. Scientific Reports, 7(1), 1-9. https://doi.org/10.1038/s41598-017-00497-x

• Shahruddin, S. S., Ideris, N., Abu Bakar, N. F., Ahmad, A. L., & Lah, N. F. C. (2021). Influence of membrane character on suppression of coffee-ring effect. Materials Today: Proceedings, 46, 1870-1874. https://doi.org/10.1016/j.matpr.2021.01.761

• Zhuang, J. L., Zhang, Y., Liu, X. Y., Wang, C., Mao, H. L., Du, X. & Tang, J. (2019). Edge enriched self-assembly of Au nanoparticles: Coffee-ring effect during microcontact printing via agarose stamps. Applied Surface Science, 469, 90-97. https://doi.org/10.1016/j.apsusc.2018.10.261