Heat dissipation in slab gel electrophoresis: The effect of embedded TiO2 nanoparticles on the thermal profiles

Abstract

Despite the fast development of novel and high-resolution electrophoresis techniques such as capillary-based methods and microfluidic devices, the slab gel electrophoresis is still a popular method for the separation of biomolecules in medicine and biology. It is a low cost and simple method and offers high throughput. However, this technique is limited to low voltages leading to slow separations. Producing the heat during the electrophoresis known as Joule heating inevitably leads to a rise in the gel temperature. For the first time, this work offers a whole gel temperature measurement by using a thermal camera which presents accurate temperature profiles in the gel with a resolution of more than 10 pixel/mm2 and a precision of 0.1 °C. Titania, TiO2, nanoparticles (NPs) were embedded into the polyacrylamide (PA) gel to improve the electrophoretic separation of proteins. By embedding 0.025% w/v TiO2 NPs, heat dissipation increases by 16.5% at applied voltage of 200 V compared with that of PA gel with no embedded TiO2 NPs. The thermal images showed that the composite gel was 2.5 °C in average cooler than PA gel after 15 min of electrophoresis run at 200 V. The maximum separation voltage increased by 30 V in the composite PA/TiO2 gel compared with the pure PA gel. Moreover, the average number of theoretical plates over the 10 protein peaks, as a criterion of separation performance, increased by about 63% at 180 V when TiO2 NPs were included into the gel.