Towards homogenous multiwell plate based pH sensors using a responsive triangulenium dye and an ATTO-647 reference...

Area of Science:

• Analytical Chemistry
• Biotechnology
• Sensor Technology

Background:

• Accurate pH monitoring is critical in diverse fields, including cheese making and in vitro fertilisation (IVF).
• Current methods for monitoring pH in cheese starter cultures rely on conventional pH electrodes.
• Existing technologies like blood gas analysers are used for patient monitoring but not widely adopted for other applications like IVF.

Purpose of the Study:

• To develop a novel homogeneous multiwell plate sensor for pH monitoring in small liquid volumes.
• To achieve sensitivity comparable to conventional pH electrodes for improved pH measurement.
• To assess the sensor's performance and robustness for applications such as IVF.

Main Methods:

• A homogeneous sensor was designed using a pH-responsive triangulenium dye on polystyrene nanoparticles and a freely diffusing reference dye.
• Sensor components and the multiwell plate design were tested for performance and robustness in triplicate.
• Measurements were conducted in cuvettes, progressing to microwells and smaller sample volumes, including IVF buffers.

Main Results:

• The homogeneous sensor demonstrated sensitivity comparable to traditional pH electrodes.
• The sensor operated effectively within the pH range relevant to in vitro fertilisation buffers.
• The chosen commercial reference dye was found to be unsuitable for the sensor system, limiting precision.

Conclusions:

• The homogeneous sensor design is fundamentally sound for pH monitoring.
• Achieving the target precision of ΔpH = 0.01 requires the identification and implementation of a more suitable reference dye.
• Further development with an optimized reference dye could enable widespread application in sensitive areas like IVF.