Lopes Carlos E C, de Faria Lucas V, Araújo Diele A G, Richter Eduardo M, Paixão Thiago R L C, Dantas Luiza M F, Muñoz Rodrigo A A, da Silva Iranaldo S
Chemistry Technology Department, Federal University of Maranhão, 65080-805, São Luís, Maranhão, Brazil.
Institute of Chemistry, Federal University of Uberlândia, 38408-100, Uberlândia, MG, Brazil.
Talanta. 2023 Jul 1;259:124536. doi: 10.1016/j.talanta.2023.124536. Epub 2023 Apr 11.
Antibiotics such as tetracycline (TC) are widely prescribed to treat humans or dairy animals. Therefore, it is important to establish affordable devices in laboratories with minimal infrastructure. 3D printing has proven to be a powerful and cost-effective tool that revolutionizes many applications in electrochemical sensing. In this work, we employ a conductive filament based on graphite (Gr) and polylactic acid (PLA) (40:60; w/w; synthesized in our lab) to manufacture 3D-printed electrodes. This electrode was used "as printed" and coupled to batch injection analysis with amperometric detection (BIA-AD) for TC sensing. Preliminary studies by cyclic voltammetry and differential pulse voltammetry revealed a mass transport governed by adsorption of the species and consequent fouling of the redox products on the 3D printed surface. Thus, a simple strategy (solution stirring and application of successive potentials, +0.95 V followed by +1.2 V) was associated with the BIA-AD system to solve this effect. The proposed electrode showed analytical performance comparable to costly conventional electrodes with linear response ranging from 0.5 to 50 μmol L and a detection limit of 0.19 μmol L. Additionally, the developed method was applied to pharmaceutical, tap water, and milk samples, which required minimal sample preparation (simple dilution). Recovery values of 92-117% were obtained for tap water and milk samples, while the content found of TC in the capsule was close to the value reported by the manufacturer. These results indicate the feasibility of the method for routine analysis involving environmental, pharmaceutical, and food samples.
四环素（TC）等抗生素被广泛用于治疗人类或奶牛。因此，在基础设施最少的实验室中建立价格合理的设备非常重要。3D打印已被证明是一种强大且具有成本效益的工具，它彻底改变了电化学传感中的许多应用。在这项工作中，我们使用基于石墨（Gr）和聚乳酸（PLA）（40:60；w/w；在我们实验室合成）的导电细丝来制造3D打印电极。该电极“直接使用”，并与采用安培检测的批式进样分析（BIA-AD）联用进行TC传感。通过循环伏安法和差分脉冲伏安法进行的初步研究表明，物质的吸附主导了传质过程，并且氧化还原产物在3D打印表面上会产生污垢。因此，一种简单的策略（溶液搅拌和施加连续电位，先+0.95 V然后+1.2 V）与BIA-AD系统相结合以解决此问题。所提出的电极显示出与昂贵的传统电极相当的分析性能，线性响应范围为0.5至50 μmol/L，检测限为0.19 μmol/L。此外，所开发的方法应用于药物、自来水和牛奶样品，这些样品所需的样品前处理最少（简单稀释）。自来水和牛奶样品的回收率为92-117%，而胶囊中TC含量的测定值接近制造商报告的值。这些结果表明该方法用于涉及环境、药物和食品样品的常规分析的可行性。
