Credit: Weiyu Xiao et al.
Researchers from Xi'an Jiaotong-Liverpool University, China, have developed microfluidic pH sensors that can be used for small sample sizes. The sensors could have extensive applications in small-volume pH detection, something the research community has been lacking.
Current methods for measuring pH are typically only suitable for bulk solutions and are either too fragile or not sensitive enough to measure small volumes. In the study, published in Microchimica Acta, the researchers outline a newly developed sensor to solve these problems. "Our solution needed to be environmentally friendly, durable, and sensitive enough to accurately measure pH variation in just a few microliters of samples," said Dr. Qiuchen Dong.
Common commercially viable options include highly subjective testing strips or fragile glass electrodes to detect pH. While these work for bulk solutions, they fall short when attempting to measure the pH of just a few microliters of sample. To solve these issues, the researchers utilized novel materials and methods to create a pH sensor that is sensitive enough for microliter applications while being robust enough to withstand frequent use.
In the new pH sensor, the fluid flows through microfluidic channels before crossing three electrodes constructed of light-responsive materials. "Our solution to the problem relies on developing microfluidic channels and electrodes using photolithography, a method often used in the semiconductor manufacturing industry," said Dong. The sensors detect minor variations in proton counts, leading to a highly accurate sensor.
The team has a pending patent on the sensor and is currently working with developers to integrate the technology into their laboratory equipment. The researchers believe there are extensive commercial applications for the new tech and plan to continue development on the sensors.