“…The use of phosphate sensors/receptors, coupled with optical detection has been researched quite extensively. The detection has normally been colorimetric (Tobey & Anslyn, 2003;Han & Kim, 2002) and luminescence/fluorescence (Yaqoob et al, 2004;Lin et al, 2006;Sun et al, 2008;Ganjali et al, 2011;Anzenbacher et al, 2000;Ojida et al, 2002Ojida et al, , 2004Hamachi, 2009;Sessler et al, 2003;Deetz & Smith, 1998;Du et al, 2008;Fabbrizzi et al, 2002). These methods have yielded detection limits varying from milligrams to micrograms per litre but which are higher than the much lower detection limits required for environmental applications.…”