Sensors for detecting and distinguishing metals in a sample comprise phenol group-containing azo dyes, the phenol group having one hydroxy involved in reversible metal ion binding and a second hydroxy alkylated to an optically transparent substrate. The sensors have utility for detecting chromium, calcium, magnesium, copper, mercury, nickel, zinc, cobalt, manganese, cadmium, lead, tin, aluminum, potassium, sodium, or arsenic ions in a sample.

Provided herein are dyes for detecting and distinguishing metals in a sample, as well as compositions and methods comprising the same.

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A compound represented by formula:

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and a treated filler having the compound on at least a portion of its surface. R is hydrogen or alkyl. X is alkylene, arylalkylene, or alkylarylene, each optionally interrupted by at least one of an ether, thioether, amine, amide, ester, thioester, carbonate, thiocarbonate, carbamate, thiocarbamate, urea, or thiourea, with alkylene optionally interrupted by arylene. W is hydroxyl, a sulfonic acid group, a phosphonic acid group, carboxylic acid group, NHR.sup.1, epoxy, or Si(Y).sub.x(Z).sub.3-x. Y is alkyl, aryl, arylalkylenyl, or alkylarylenyl. Z is halide, hydroxyl, alkoxy, aryloxy, acyloxy, polyalkyleneoxy, O covalently bonded to the surface of the filler, or O bonded to another silicon atom, and x is 0 or 1. A composition including the treated filler, a method of making the treated filler, and a method of determining the degree of cure of a curable polymeric resin are also disclosed.

A compound represented by formula (I): and a treated filler having the compound on at least a portion of its surface. R is hydrogen or alkyl. X is alkylene, arylalkylene, or alkylarylene, each optionally interrupted by at least one of an ether, thioether, amine, amide, ester, thioester, carbonate, thiocarbonate, carbamate, thiocarbamate, urea, or thiourea, with alkylene optionally interrupted by arylene. W is hydroxyl, a sulfonic acid group, a phosphonic acid group, carboxylic acid group, NHR.sup.1, epoxy, or Si(Y).sub.x(Z).sub.3-x. Y is alkyl, aryl, arylalkylenyl, or alkylarylenyl. Z is halide, hydroxyl, alkoxy aryloxy, acyloxy, polyalkyleneoxy, O covalently bonded to the surface of the filler, or O bonded to another silicon atom, and x is 0 or 1. A composition including the treated filler, a method of making the treated filler, and a method of determining the degree of cure of a curable polymeric resin are also disclosed. ##STR00001##