Ultrasensitive Fluorescent Biosensor for Creatinine Determination in Human Biofluids Based on Water Soluble Rhodamine B Dye‐Au³⁺ ions Conjugate

Abstract

Simple, ultrasensitive and selective diagnostic tool is required for the quantification of creatinine in human biofluids. To the best of our knowledge, we are reporting the second fluorescent as well as colorimetric biosensor for creatinine with a very good linear range. We have utilized a simple water soluble Rhodamine B dye as a probe because of its excellent emitting properties and quantum yield. As a colorimetric biosensor, the dye has selectively detected the Au3+ ions in a ratiometric aspect through ICT mechanism among all other interfering metal ions. When the creatinine was introduced, the Au3+ ions were gradually released from the dye and binded with the creatinine which finally enhanced the fluorescent intensity. The Stern Volmer quenching constant Ksv was found to be 2.6 x 109 M−1. As a colorimetric biosensor, the limit of detection and linear range for creatinine are found to be 54 nM and 100 nM to 15 μM, respectively. Under the optimized condition, the fluorescent biosensor has detected the creatinine within the linear range of 10 nM to 1.2X10−3M along with the LOD of 5 nM. The linear range of developed biosensor implies that the biosensor can be applied for clinical diagnosis of muscle disorder (creatinine level < 40μM), extreme renal problem (creatinine level=1000μM). We have extended the application of this developed biosensor for the determination of creatinine in human urine sample and achieved a very good recovery.Introduction

Optical Supramolecular Sensing of Creatinine

“…The level of creatinine ( Cr , see Figure ) in human bodily fluids is a widely applied clinical indicator for monitoring kidney and renal functions. , Creatinine is a metabolic waste product, being related to muscle activity, and any anomalous secretion due to organ malfunction leads inevitably to higher concentrations of Cr in blood serum and/or urine. Methods for molecular biosensing of creatinine using simple fluorescent probes or in combination with bioconjugates have been reported. − While these latter approaches rely on unspecific interactions between creatinine and the probe molecule, supramolecular sensing offers distinct benefits for the design of selective and specific sensors by building on size, shape, and function complementarity between the receptor and analyte. Unfortunately, most synthetic receptors designed for creatinine binding are flat and edge-functionalized with divergent hydrogen bonding motifs. − These characteristics make them a nonideal choice for supramolecular sensing design.…”

Synthesis of a 1,4‐Bis[2‐(5‐thiophen‐2‐yl)‐1‐benzothiophene]‐2,5‐dioctyloxybenzene Pentamer for Creatinine Detection

“…Nonetheless, in the computational work reported by Francois et al ., [28] a strong NH−S bond was observed. It is also reported that the strengths of NH−S and NH−O are dependent on the angle of the hydrogen bond [28] …”

“…The interaction between NH−S is considered weak compared to NH−O, because of the low electronegativity value of S (2.58) in comparison to O (3.40). Nonetheless, in the computational work reported by Francois et al ., [28] a strong NH−S bond was observed. It is also reported that the strengths of NH−S and NH−O are dependent on the angle of the hydrogen bond [28] …”

“…It is also reported that the strengths of NHÀ S and NHÀ O are dependent on the angle of the hydrogen bond. [28] However, Biswal and Wategaonkar [27] report that NHÀ S hydrogen bonding strength is stronger than the NHÀ O hydrogen bonding. It is suggested that in the NHÀ S hydrogen bonding, a greater dispersion contribution to the stabilization energy and greater redshifts in NÀ H stretch was observed in comparison to the NHÀ O hydrogen bonding.…”

High stability resistive switching mechanism of a screen-printed electrode based on BOBZBT2 organic pentamer for creatinine detection

“…1 c—II. This is due to the gradual relaxation between BOBzBT 2 and the creatinine molecule 25 . Despite that, two BOBzBT 2 characteristic peaks as obtained previously, were preserved.…”