The need for an improved sensor performance is always encouraging us towards exploring new materials. Following the invention of dendrimers, the possibility was recognised of using them for improving optical sensor performance. Their more important aspects are their two main structural properties: three-dimensional structure and multiple terminal functional groups. In this review, firstly a brief introduction to dendrimers is provided with the focus on PAMAM dendrimers and optical sensors. Recent advances have been reported in those PAMAM dendrimer-based optical sensors, which are used for the detection of pH, cations, and other analyte.

This study presents chemical modification of a Rhodamine B (RhB) sensor probe by ethylenediamine (EDA), and investigation of its spectral as well as sensor properties to the various metals. The synthesised N-(Rhodamine-B)-lactam-ethylenediamine (RhB-EDA) fluorescent probe shows interesting optical sensor properties, and high sensitivity and selectivity to Ag+ ions among all the tested metal ions (K+, Mg2+, Cu2+, Ni2+, Fe2+, Pb2+, Na+, Mn2+, Li+, Al3+, Co2+, Hg2+, Sr2+, Ca2+, Ag+, Cd2+ and Zn2+), while the well-known Rhodamine B (RhB) fluorescent probe shows much less sensitivity to Ag+ ions, but high sensitivity to Fe2+ ions. The novel fluorescent sensor probe RhB-EDA has the capabilities to sense Ag+ ions up to µM ranges by using the fluorescence quenching approach. The probe displayed a dynamic response to Ag+ in the range of 0.43 × 10−3–10−6 M with a detection limit of 0.1 μM. The sensing system of an RhB-EDA novel fluorescent probe was optimised according to the spectral properties, effect of pH and buffer, photostability, incubation time, sensitivity, and selectivity. Since all the spectral and sensing properties were tested in green aqueous media, although many other similar sensor systems rely on organic solvent solutions, the RhB-EDA sensing probe may be a good candidate for measuring Ag+ ions in real-life applications.