In this study, a novel, simple and sensitive ratiometric fluorescence method is presented for the detection of very low quantities of the carbaryl in Iranian apple using cadmium telluride quantum dots (CdTe QDs) nanoprobe. The principle of the proposed strategy relies on the rapid hydrolysis of the carbaryl under an alkaline condition and production of the 1-naphthol with a blue emission at 470 nm. Besides, using the CdTe QDs with a yellow emission at 580 nm, as a reference, improves the visual tracking of carbaryl through changes in color tonality. The herein described methodology is applied for enzyme-free visual detection of carbaryl with satisfactory results in the presence of other common pesticides in Iranian apple sample. Additionally, the calculated limit of detection (LOD) of 0.12 ng mL⁻¹ for carbaryl is much lower than the maximum residue limits of carbaryl warned value reported by the European Union and United States pesticides database, which is so promising for carbaryl sensing in the monitoring of fruits. Furthermore, the ability of the proposed method for the detection of carbaryl residues in Iranian apple was confirmed by the high-performance liquid chromatography (HPLC) method as a standard method through statistical analysis. This fast and highly sensitive naked-eye ratiometric sensor may hold great promise to provide the technical support for the rapid and valid detection of other targets in food safety fields.

在这项研究中，提出了一种新颖，简单，灵敏的比例荧光方法，该方法使用碲化镉量子点（CdTe QDs）纳米探针检测伊朗苹果中的极少量甲萘威。所提出的策略的原理依赖于在碱性条件下西芳基的快速水解和在470 nm处发出蓝色发射光的1-萘酚的产生。此外，使用在580 nm处发黄光的CdTe QD作为参考，可通过色阶变化来改善西维因的视觉追踪。本文所述的方法适用于无酶肉眼检测西维因，在伊朗苹果样品中存在其他常见农药的情况下，结果令人满意。此外，计算出的检出限（LOD）为0.12 ng mL ^-1西维因的残留量远低于欧盟和美国农药数据库报告的西维因的最大残留限量，这对于监测水果中的西维因很有希望。此外，通过统计分析，通过高效液相色谱（HPLC）方法作为标准方法，证实了所提出方法检测伊朗苹果中西芳基残留的能力。这种快速且高度灵敏的肉眼比例传感器可以为快速有效检测食品安全领域中的其他目标提供技术支持。