Al³⁺-Responsive Ratiometric Fluorescent Sensor for Creatinine Detection: Thioflavin-T and Sulfated-β-Cyclodextrin Synergy

Abstract

Kidney disorders are a rising global health issue, necessitating early diagnosis for effective treatment. Creatinine, a metabolic waste product from muscles, serves as an ideal biomarker for kidney damage. The existing optical methods for creatinine detection often involve labor-intensive synthesis processes and present challenges with the aqueous solubility and sensitivity to experimental variations. In this study, we introduce a straightforward fluorescence "turn-on" ratiometric sensor system for creatinine detection in aqueous media with a limit of detection of 0.5 μM. The sensor is based on sulfated-β-cyclodextrin (SCD)-templated Haggregate of a commercially available, ultrafast rotor dye thioflavin-T (ThT). The Al 3+ ion-induced dissociation of ThT−SCD aggregates, followed by reassociation upon creatinine addition, generates a detectable signal. The modulation of monomer/aggregate equilibrium due to the disassembly/reassembly of the ThT−SCD system under Al 3+ /creatinine influence serves as the optimal strategy for ratiometric creatinine detection in aqueous media. Our sensor framework offers several advantages: utilization of the readily available dye ThT, which eliminates the need for a laborious synthesis of custom fluorescent probes; ratiometric sensing, which improves quantitative analysis accuracy; and compatibility with complex aqueous media. The sensor's practical utility has been successfully demonstrated in artificial urine samples. In summary, our sensor system represents a significant advancement in the rapid, selective, and sensitive detection of the clinically crucial bioanalyte creatinine, offering potential benefits for the early diagnosis and management of kidney disorders.

Ratiometric fluorescence detection of Hg2+ based on gold nanocluster/carbon quantum dots nanohybrids

“…However, most of these methods are based on the change in intensity of a single fluorescence peak as the signal output, which is easily affected by the instrumental stability and experimental conditions, such as temperature, solvent polarity, probe distribution and excitation power. 20,21 Ratiometric fluorescence assay can greatly minimize the influence of the instrument, background, and environmental signals, and improve quantification and accuracy through the measurement of the ratio of two signals. 22,23…”

Target-Imprinted Polyaniline/Nb2O5 Nanoparticles as Electrochemical Interfaces for Monitoring Kidney Function

“…A decade ago, Randviir and Banks summarized electrochemical and nonelectrochemical methods for creatinine monitoring, providing critical insights and underlining major challenges. In this context, the ongoing research on POC Cre diagnostics continues to drive innovation, exploring new materials and methods to enhance sensitivity, selectivity, and portability in Cre sensors. , For instance, a recently reported fluorescent turn-on, ratiometric Cre sensor using sulfated-β-cyclodextrin-templated thioflavin-T dye could detect Cre down to 0.5 μM . Ming et al developed an electrochemical sensor based on Cu-MOF/MWCNT loaded with Cu nanoparticles that demonstrated an 11.3 nM detection limit and linear response in the 0.05–40 μM Cre concentration range.…”

“…To combat this issue and increase survival rates through timely interventions, it is essential to develop an economical and noninvasive POC method for routine monitoring. CKD is often characterized by an increase in creatinine (Cre) levels in bodily fluids such as saliva, serum, and urine, making Cre a crucial biomarker for diagnosing CKD and other renal problems. , …”