Paper-strip ion-selective electrodes with nanomolar detection limits exhibit high selectivity for target ion and high reproducibility
Ion-selective electrodes (ISEs) are critical for ion detection. Paper-based ISEs are a simple, low cost, and disposable alternative to conventional solid-contact ISEs. However, widespread use of paper-based ISEs has been limited due to poor detection limits (in the micromolar range), reliability, and selectivity.
This technology relates to ultra-sensitive paper-based ISEs that display high selectivity for their ion target and high reproducibility. Unlike other currently available ISEs, which require a pre-conditioning step in an analyte ion solution prior to measurement, these novel ISEs require no pre-conditioning and have demonstrated unprecedented limits of detection (2.5×10-9, 2.7×10-8, and 3.3×10-8 M) for cadmium, silver, and potassium ions, respectively. In addition to traditional ion detection, these new paper-strip ISEs can be used for in-situ analysis of bodily fluids (e.g., sweat, tears, etc.) and to assay biomolecules (e.g., proteins and DNA), providing cost-effective medical diagnostics. These electrodes can also be fabricated with glass, silica, or plastic.
• Low-cost alternative to solid-contact ISEs
• Ultra-sensitive, lower limits of ion detection in nanomolar range
• Improved applicability, reproducibility, reliability, and selectivity
• Does not require pre-conditioning, allowing for immediate on-site analysis
• Biomedical analysis
• Environmental analysis
• Industrial and food processing