Electrochemical Phosphate Sensors Using Silver Nanowires Treated Screen Printed Electrodes

Essential biomolecules of the human body and plant growth depend upon the proper amount of phosphate ions. Phosphorus has critical values in both agricultural and biomedical applications. There is a need for inexpensive, portable, repeatable, highly sensitive, and field deployable sensors with wide detection range to monitor the health of water system and field soil. This paper aims to develop an electrochemical phosphate sensor using novel ammonium molybdate tetrahydrate/silver nanowires (AMT/AgNWs) modified screen printed electrode (SPE) for phosphate detection to achieve simplicity, high sensitivity, wide detection range, and high repeatability and portability. The cyclic voltammetry measurements exhibited the sensitivities of AMT modified SPE without and with AgNWs are
$0.1~\mu \text{A}/\mu \text{M}$
and
$0.71~\mu \text{A}/\mu \text{M}$
, respectively. The use of highly conductive AgNWs significantly increased the sensitivities of the AMT/SPE. Besides, AgNWs and AMT modified SPE (AMT/AgNWs/SPE) showed a very wide detection range of
$5~\mu \text{M}$
–1 mM. The maximum relative standard deviation of around 5% confirms the repeatability of the proposed sensor. This paper suggests that AMT/AgNWs/SPE is promising for simple, low-cost, and portable phosphate ion detection.