An electrochemical sensor for phosphate detection in body fluids was developed based on the hydration transition of magnesium hydrogen phosphate (newberyite, MgHPO₄·3H₂O). The sensor was fabricated through incubation of a multi-walled carbon nanotube/Nafion (MWCNT/Nafion) modified glassy carbon electrode (GCE) in magnesium phosphate solution, where MgHPO₄·3H₂O was self-assembled on the electrode surface (denoted as MgP/MWCNT/Nafion). An electrooxidation peak at 1.0 V vs. Ag/AgCl was observed when the as-prepared electrode was subjected to a differential pulse voltammetry (DPV) scan in the presence of phosphate in acetate solution. When the DPV scan was performed in 0.4 – 1.3 V vs. Ag/AgCl, a linear relationship was observed between the peak height and the phosphate concentration in the range from 0.01 to 25 μM in the presence of 0.1 mM Mg²⁺ in the acetate solution with a limit of detection of 32 nM. And the sensor was successfully applied for phosphate detection in human urine and saliva samples with recoveries of 94.7 – 104.4 and 96 – 103.3%, respectively.

基于磷酸氢镁（新辉石，MgHPO ₄ ·3H ₂ O）的水合转变，研制了一种用于体液磷酸盐检测的电化学传感器。该传感器是通过在磷酸镁溶液中孵育多壁碳纳米管/Nafion（MWCNT/Nafion）修饰的玻碳电极（GCE）而制成的，其中MgHPO ₄ ·3H ₂ O在电极表面自组装（表示为MgP/MWCNT/Nafion）。当在乙酸盐溶液中存在磷酸盐的情况下对制备的电极进行差分脉冲伏安法 (DPV) 扫描时，观察到在 1.0 V vs. Ag/AgCl处的电氧化峰。当 DPV 扫描在 0.4 – 1.3 V与Ag/AgCl，在乙酸盐溶液中存在 0.1 mM Mg ^{2+ 时，}在0.01 至 25 μM 的范围内观察到峰高与磷酸盐浓度之间的线性关系，检测限为 32 nM。该传感器成功应用于人体尿液和唾液样品中的磷酸盐检测，回收率分别为 94.7-104.4% 和 96-103.3%。