Spermine and Spermidine Detection through Restricted Intramolecular Rotations in a Tetraphenylethylene Derivative

Mariana Barros,José Antonio Sáez,Pablo Gaviña,Margarita Parra,Ana María Costero,Samuel Ceballos,Salvador Gil,Pau Arroyo

doi:10.3390/chemosensors10010008

Abstract

Biogenic polyamines, especially spermine and spermidine, are associated with cell growth and development. These amines can be found at high concentrations in the tumor cells, tissues, and urine of cancer patients. In contrast, spermidine levels drop with age, and a possible connection between low endogenous spermidine concentrations and age-related deterioration has been suggested. Thus, the quantification of these amines in body fluids like urine could be used in the diagnosis of different pathological situations. Here a new fluorescent molecular probe based on a tetraphenylethylene derivative is reported. This probe is able to selectively detect these amines through the enhancement of the fluorescence emission of the resulting complex. This fluorescence enhancement may be related to restricted intramolecular rotations of TPE phenyl rings induced by the analyte. Theoretical studies were carried out to shed light on the observed selectivity. Finally, the detection of these amines in urine was performed with limits of detection of 0.70 µM and 1.17 µM for spermine and spermidine, respectively.

Highlights

The development of chromogenic or fluorogenic chemosensors for detecting biologically active molecules is a continuously progressing research area. The expansion of this field is related to the many advantages of these chemosensors, such as real-time detection, low cost, easy usage protocols, and naked-eye detection, among others [1,2,3]
Most chemosensors are designed using the binding site signaling unit approach, in which two subunits, one able to interact with the analyte and the other with chromogenic or fluorogenic properties, are covalently bound
The two branches ending with carboxylic acids allow it to strongly interact with the longer biogenic aliphatic polyamines

Summary

Introduction

The development of chromogenic or fluorogenic chemosensors for detecting biologically active molecules is a continuously progressing research area. This, in turn, will lead to variations in the color or fluorescence emission of the chemosensor [4,5] In this way, the information at the molecular level (presence of the analyte) is amplified at a macroscopic level (signaling event). Even though chromogenic probes are very appealing, fluorescent systems usually allow lower limits of detection to be obtained [6]. In this sense, many fluorescent organic units, such as coumarins [7], dansyl derivatives [8], cyanines [9], and BODIPYs [10], among others, have been used

Methods

Discussion

Conclusion