The world’s first micro-sensor for simultaneous determination of pH and chloride ions was born

According to news from foreign media, Belgian and Dutch technicians developed the world's first miniature sensor that can simultaneously measure pH and chloride (Cl-) levels in fluids. This sensor may have better sensitivity, accuracy, and response time, and at the same time much smaller, and later may also be cheaper.

Researchers at the Imec and Holst Centers (Leuven, Belgium and Eindhoven, The Netherlands) believe they have the world's first miniature sensor that can simultaneously measure pH and chloride (Cl-) levels in fluids. This innovation is necessary for accurate long-term measurements of ion concentrations in applications such as environmental monitoring, precision agriculture and personalized medical diagnostics.

With the possibility of system-on-a-chip (SoC) integration, it can achieve large-scale and cost-effective deployment in Internet of Things (IoT) settings. Its innovative electrode design has similar or better performance than the standard components used today for measuring single ion concentrations, and allows for other ion measurements.

Imec said that ion-selective membrane-based sensors are considered "gold standards" for measuring ion concentrations in many applications such as water quality, agriculture, and analytical chemistry. They consist of two electrodes - a membrane-equipped ion-sensitive electrode (ISE) and a reference electrode (RE). When these electrodes are immersed in the fluid, a potential that is proportional to the logarithm of the ion activity in the fluid is generated, thereby constituting a measure of the concentration. However, the accuracy of this sensor depends on the long-term stability of miniaturized REs, which Imec said has now overcome this problem.

"The common problem with this design is that ions leaching from the internal electrolyte cause the sensor to drift over time," said Marcel Zevenbergen, senior researcher at the Imec/Holst Center. "In order to suppress this leaching, we designed and manufactured REs with microfluidic channels as junctions and combined with solid-state cerium oxide (IrOx) and silver chloride (AgCl) electrodes fabricated on silicon substrates as pH and Cl, respectively - The indicating electrode Our tests have proved that this is a long-term stable solution, the sensor exhibits the same or better sensitivity, accuracy and response time as the existing solution, and at the same time is much smaller and may be cheaper in the future. ”

“We provide groundbreaking sensing and analysis solutions for the Internet of Things,” said John Baekelmans, Managing Director of Imec in the Netherlands. "This new multi-ion sensor is one of a series of products that the Holst Center is currently developing with its partners to form an Internet of Things sense. For each sensor, the goal is to be able to mass produce, wirelessly communicate, and work. Optimized and miniaturized packages provide performance that is superior to existing leading-edge sensor performance."

(Original Title: The world's first miniature sensor for simultaneous determination of pH and chloride levels in fluids)