The illicit consumption of heroin is an increasing concern in our society. For this reason, rapid analytical methods to seize heroin samples in the field are of paramount importance to hinder drug trafficking, and thus prevent the availability of heroin in the drug market. The present work reports on the enriched electrochemical fingerprint of heroin, allowing its selective detection in street samples, based on the use of electrochemical pretreated screen printed electrodes (p-SPE). The voltammetric identification is built on two oxidation peaks of both heroin and its degradation product 6-monoacetylmorphine (6-MAM), generated in alkaline conditions. Interestingly, an anodic pretreatment of the screen printed electrodes (SPE) shifts the peak potential of paracetamol (the most encountered cutting agent in heroin seizures), allowing the detection of 6-MAM peak, overlapping with the paracetamol signal in the case of untreated SPE. Subsequently, the characterization of the p-SPE with scanning electron microscopy, cyclic voltammetry, electrochemical impedance spectroscopy, Raman and Fourier transform infrared (FTIR) spectroscopy is provided to demonstrate local changes on the surface of the electrode. From an analytical perspective, p-SPE provide higher sensitivity (0.019 μA μM⁻¹), excellent reproducibility (6-MAM, RSD = 2.85%, and heroin RSD = 0.91%, n = 5) and lower limits of detection (LOD) (5.2 μM) in comparison to untreated SPE. The proposed protocol which integrates a tailor-made script is interrogated against common cutting agents, and finally, validated with the screening of 14 street samples, also analyzed by standard methods. Besides, a comparison with portable spectroscopic techniques on the confiscated samples shows the better performance of the electrochemical strategy. Overall, this sensing approach offers promising results for the rapid on-site profiling of suspicious heroin samples, also in the presence of paracetamol.

海洛因的非法消费是我们社会日益关注的问题。因此，在现场缉获海洛因样品的快速分析方法对于阻碍毒品贩运至关重要，从而阻止了海洛因在毒品市场的供应。本工作报告了海洛因的丰富的电化学指纹图谱，基于对电化学预处理的丝网印刷电极（p-SPE）的使用，可在街道样品中进行选择性检测。伏安法鉴定建立在碱性条件下产生的海洛因及其降解产物6-单乙酰吗啡（6-MAM）的两个氧化峰上。有趣的是，丝网印刷电极（SPE）的阳极预处理可改变扑热息痛（海洛因癫痫发作中最常见的切割剂）的峰值电势，在未经处理的SPE情况下，可检测到6-MAM峰，与对乙酰氨基酚信号重叠。随后，通过扫描电子显微镜，循环伏安法，电化学阻抗谱，拉曼和傅立叶变换红外（FTIR）光谱对p-SPE进行表征，以证明电极表面的局部变化。从分析的角度来看，p-SPE可提供更高的灵敏度（0.019μAμM^-1），优异的重现性（6-MAM，RSD = 2.85％，海洛因RSD = 0.91％，n = 5），与未处理的SPE相比，检测下限（LOD）（5.2μM）低。拟议的协议结合了量身定制的脚本，对普通切割剂进行了询问，最后，通过筛选14个街道样本进行了验证，并通过标准方法进行了分析。此外，与便携式光谱技术对没收样品进行的比较表明，电化学策略具有更好的性能。总体而言，这种感测方法为可疑海洛因样品的快速现场分析（即使在扑热息痛的情况下）也提供了令人鼓舞的结果。