Polyalkoxy substituted phthalocyanines sensitive to phenolic compounds in water

•New phthalocyanines are introduced for chemical sensing in water.•Clear trend in sensitivity and selectivity with modifications made to the Pcs.•Selectivity is governed by substituent, sensitivity mainly by metal ion center.•High sensitivity to phenolic compounds with detection limits down to 0.01mg/ml.•Highest reported sensitivity of a Pc in liquid sensing applications with the QCM.