A system for fluorescence-based detection of mercury(II) ions using a thiourea-based chemosensor

Abstract

A system for fluorescence-based detection of mercury(II) ions using a thiourea-based chemosensor, comprising: a sensor composition comprising a thiourea-based chemosensor and a fluorescence detection arrangement, wherein the thiourea-based chemosensor comprises sulfur- and nitrogen-containing functional groups configured to selectively bind mercury(II) ions present in a liquid sample, and wherein the binding of the mercury(II) ions to the chemosensor causes a measurable change in fluorescence emission indicating the presence of mercury(II) ions in the liquid sample.

Description

[0001] The present invention relates to the field of chemical sensor and analytical detection systems. In particular, the invention relates to a fluorescence-based detection system for the identification and quantification of mercury(II) ions in liquid samples using a thiourea-based chemosensor.

[0002] Mercury and its ionic forms, especially mercury(II) ions (Hg) 2+Mercury ions are among the most dangerous heavy metal pollutants found in environmental, industrial, and biological systems. Mercury contamination poses a serious risk to human health, including neurological disorders, kidney damage, and developmental impairments, and also causes long-term environmental damage due to its persistence and bioaccumulation. Therefore, the accurate and reliable detection of mercury ions at low concentrations is crucial for environmental monitoring, water quality control, and public health protection. Conventional mercury detection techniques, such as atomic absorption spectroscopy, inductively coupled plasma mass spectrometry, and related instrumental methods, are generally characterized by high sensitivity and accuracy.However, these techniques typically require expensive equipment, skilled personnel, complex sample preparation, and laboratory operation. These limitations restrict their suitability for rapid, field-based, or routine monitoring applications. In response to these challenges, chemical chemosensors, particularly fluorescence-based sensors, have attracted considerable attention due to their simplicity, rapid response time, and potentially high sensitivity. Several organic ligands and sensor materials have been described for the detection of mercury ions. Despite these efforts, many existing fluorescence sensors exhibit one or more drawbacks, including insufficient sensitivity at trace levels, poor selectivity in the presence of competing metal ions, limited stability in practical solvent systems, and inadequate reproducibility in real-world sample matrices.Another limitation of many described mercury sensors is the lack of a clear correlation between molecular structure and sensor performance. In several cases, sensor mechanisms are proposed without sufficient structural or electronic validation, making it difficult to predict sensor behavior, optimize performance, or ensure long-term reliability. Furthermore, a number of known sensors exhibit detection limits that are insufficient to meet increasingly stringent legal standards for mercury contamination. Therefore, there remains a need for an improved mercury detection system that overcomes the shortcomings of existing technologies. Such a system should exhibit high sensitivity and selectivity for mercury. 2+The sensors must contain ions, function reliably in practical solvent environments, and enable accurate detection in real water samples without significant interference from other metal ions. Furthermore, there is a need for a sensor system whose performance is supported by clearly defined molecular interactions and stable sensor behavior to ensure consistent and reliable operation in practical applications.

[0003] To solve this problem, the present invention offers a system for fluorescence-based detection of mercury(II) ions using a thiourea-based chemosensor.

[0004] The system works effectively at trace concentrations, including in the nanomolar range, thus meeting the requirements for early and reliable detection of mercury impurities.

[0005] The system exhibits high selectivity towards mercury(II) ions in the presence of other metal ions, thereby minimizing interference and false alarms.

[0006] The system uses a thiourea-based chemosensor which, upon interaction with mercury(II) ions, produces a distinct and measurable fluorescence reaction.

[0007] The system is stable and reproducible in practical solvent environments, making it suitable for environmental water analysis and routine monitoring applications.

[0008] The system can be applied with high accuracy and precision to real water samples, including tap water and well water.

[0009] The system is simple in design, cost-effective, and suitable for both laboratory use and on-site analysis.

[0010] The system overcomes the limitations of conventional mercury detection techniques, including complex operation, limited mobility, and high costs.

[0011] The system offers a robust and reliable mercury detection system suitable for environmental monitoring, industrial inspections and public health applications.

[0012] The present invention relates to a system for the fluorescence-based detection of mercury(II) ions using a thiourea-based chemosensor. The system is configured to selectively interact with mercury ions present in a liquid sample and generate a measurable fluorescence reaction corresponding to the presence and concentration of mercury(II) ions. According to the invention, the system comprises a sensor assembly containing a thiourea-based chemosensor dispersed in a suitable solvent medium, and a fluorescence detection arrangement configured to excite the sensor assembly and measure changes in fluorescence emission.Upon exposure to mercury(II) ions, the chemosensor undergoes a specific interaction that leads to a detectable change in fluorescence intensity, enabling reliable identification and quantitative assessment of mercury ions. The system exhibits high sensitivity to mercury(II) ions and allows detection at trace concentrations, including the nanomolar range. Furthermore, the system is characterized by high selectivity, with the fluorescence response to mercury(II) ions being essentially unaffected by the presence of other metal ions commonly found in environmental and industrial samples. The fluorescence-based detection system is stable and reproducible in practical solvent environments and is suitable for use in real water matrices such as tap water and well water.The system delivers accurate and precise detection results with minimal matrix interference, thus supporting its applicability in environmental monitoring and water quality analysis. Advantageously, the system offers a simple, cost-effective, and rapid detection platform compared to conventional mercury analysis techniques, which require complex instruments and extensive sample preparation. The system is suitable for both laboratory analyses and on-site and routine monitoring applications.

[0013] The present invention relates to a system for the fluorescence-based detection of mercury(II) ions using a thiourea-based chemosensor, wherein the system is configured to selectively interact with mercury ions present in a liquid sample and generate a measurable fluorescence reaction that indicates the presence and concentration of mercury(II) ions. The system comprises a sensor composition containing a thiourea-based chemosensor dissolved or dispersed in a suitable solvent medium, and a fluorescence detection arrangement configured to excite the sensor composition at a predetermined wavelength and monitor fluctuations in the fluorescence emission intensity.The thiourea-based chemosensor contains sulfur and nitrogen donor functional groups that exhibit a strong and selective affinity for mercury(II) ions, resulting in a pronounced change in fluorescence behavior upon binding with mercury ions. The system maintains high selectivity for mercury(II) ions even in the presence of other metal ions commonly found in environmental and industrial samples, thereby reducing interference and false-positive reactions. The fluorescence-based reaction enables the detection of mercury ions at trace concentrations, including the nanomolar range, allowing for the early identification of mercury contamination.The system exhibits stable and reproducible performance in practical solvent environments and maintains reliable fluorescence properties when applied to real water matrices such as tap water and well water, with minimal influence from background components. The detection system supports the quantitative assessment of mercury(II) ion concentration by correlating the fluorescence response with the mercury content, thus enabling accurate and precise analysis. Advantageously, the system is easy to configure, cost-effective, and quick to deploy, offering a practical alternative to conventional mercury detection techniques that rely on complex instruments, extensive sample preparation, and laboratory-based analyses. It is suitable for both laboratory use and field environmental monitoring, as well as routine water quality assessment.