This study describes the amperometric detection of salivary α-amylase (sAA) in human saliva samples using screen-printed carbon electrodes (SPCE). The proposed method was based on the indirect determination of sAA in a sequence of two chemical reactions. Basically, the first reaction is the hydrolysis of starch by sAA to produce maltose. Then, the generated reducing sugar promotes the conversion of [Fe(CN)₆]³⁻ into [Fe(CN)₆]⁴⁻ in a second reaction. Different parameters, such as pH, reaction time, sAA volume and starch concentration were thoroughly optimised. The best electrochemical response was found using 5 mmol L⁻¹ NaOH (pH = 12), reaction time of 20 min, sAA volume of 15 μL and 0.5% (w/v) starch. The analytical performance revealed good linear correlation for sAA concentration levels between 100 and 1200 U mL⁻¹. The achieved limit of detection (LOD) and sensitivity values were 1.1 U mL⁻¹ and 10.7 μA/(log U mL⁻¹), respectively. The proposed electrochemical sensor exhibited great selectivity. The amperometric response for sAA was recorded in the presence of different glucose levels (0.01—0.10 mmol L⁻¹) and no noticeable change was observed. The feasibility of the proposed method was investigated through the determination of sAA levels in five human saliva samples. The concentration levels found ranged between 182.8 and 1117.1 U mL⁻¹ and presented accuracy between 90 and 97%. The method reported herein emerges as a simple, inexpensive, portable, reliable and powerful tool for rapid point-of-care testing (POCT).

这项研究描述了使用丝网印刷碳电极（SPCE）在人唾液样品中进行唾液α-淀粉酶（sAA）的安培检测。所提出的方法是基于在两个化学反应序列中间接测定sAA的方法。基本上，第一个反应是sAA水解淀粉产生麦芽糖。然后，生成的还原糖在第二反应中促进[Fe（CN）₆ ] ^3-转化为[Fe（CN）₆ ] ^4-。彻底优化了pH，反应时间，sAA量和淀粉浓度等不同参数。使用5 mmol L ^-1发现了最佳的电化学反应NaOH（pH = 12），反应时间为20分钟，sAA量为15μL，淀粉含量为0.5％（w / v）。分析性能显示sAA浓度水平介于100和1200 U mL ^-1之间具有良好的线性相关性。达到的检测极限（LOD）和灵敏度值分别为1.1 U mL ^-1和10.7μA/（log U mL ^-1）。提出的电化学传感器表现出很大的选择性。在不同的葡萄糖水平（0.01-0.10 mmol L ^-1）存在下记录了sAA的安培响应，未观察到明显的变化。通过确定五个人类唾液样品中sAA水平，研究了该方法的可行性。发现的浓度水平在182.8和1117.1 U mL之间^-1且显示的准确度在90到97％之间。本文报道的方法作为用于快速即时检验（POCT）的简单，廉价，便携式，可靠且功能强大的工具而出现。