Benzimidazole Derivatives in Chemistry of Materials

**159**

**1. Introduction**

**Chapter 9**

**Abstract**

Derivatives

Optical Sensing (Nano)Materials

*Ema Horak, Robert Vianello and Ivana Murković Steinberg*

Benzimidazole derivatives are well-known biologically active substances, and therefore, they are mostly synthesised for therapeutic purposes. However, such heteroaromatic molecular systems own structure-related properties that enable a variety of applications, especially in optical science. Multifunctionality of the benzimidazole unit, such as electron accepting ability, *π*-bridging, chromogenic pH sensitivity/switching and metal-ion chelating properties, makes it an exceptional structural candidate for the design of optical chemical sensors and functional materials. Development of smart molecular sensors and novel (nano)materials is the emerging trend observed in materials and optical sensing science in general, in which the benzimidazole molecular systems strongly contribute and participate. In this chapter, we summarised recent advances in optical sensing (nano)materials that incorporate the benzimidazole structural moiety. Solid-state optical sensing systems, including self-assembled molecular materials based on benzimidazoles, are reviewed and discussed. In addition, immobilisation of benzimidazole derivatives onto or into various substrates and matrices, such as organic and inorganic polymers, bulk membranes and nanoparticles, utilising different chemical and

**Keywords:** benzimidazole, functional materials, optical sensor, solid-state,

Optical chemical sensors are widely applied in chemical science and technology, as well as in other disciplines such as biology, medicine and environmental science. They enable continuous monitoring of the target analytes and exhibit high sensitivity and fast response time. The biggest advantages of optical chemical sensors, in comparison to other sensing devices, are the economic production, ease of operation and the possibility of on-site application without reference devices, which are preferred in chemical and biological applications. Performance of every chemical sensor is primarily determined by the sensing chemistry that operates in the background, that is, the recognition unit—receptor. The receptor, the core of every optical chemical sensor, is the sensing molecule that selectively responses to the presence of the target analyte by changing the photophysical properties of the observed molecular system. Fluorescence techniques are

Based on Benzimidazole

physical methods, is presented and analysed.

absorbance, fluorescence, aggregation-induced emission

#### **Chapter 9**
