Patent ID: 8318450

Claim:
A method for determining the presence or absence of β-lactamase enzyme in a sample, the method comprising: a) contacting the sample with a β-lactamase substrate to form a contacted sample; b) incubating the contacted sample for a sufficient amount of time for a β-lactamase enzyme in the contacted sample to cleave the β-lactamase substrate to form an incubated sample; c) illuminating the incubated sample with an appropriate wavelength to obtain an illuminated sample ; and d) observing the illuminated sample whereby the presence or absence of β-lactamase enzyme in the illuminated sample is determined wherein the β-lactamase substrate has a structure of one of the following formulae: where R 1 is A is S, SO, or SO 2 ; X is O; L—Y is a thioether linked moiety formed by reaction with a quencher moiety having a structure of formula: R 2 is hydrogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl; R 3 is hydrogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl; R 4 is hydrogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl; R 5 is hydrogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl; R 6 is hydrogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl; R 7 is hydrogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl; R 8 is hydrogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl, substituted heteroaryl; R 9 is wherein W is a dye moiety; s is an integer from 0 to 5; W′ is (═O); W″ is OR 10 , NHR 11 , or halogen; wherein R 10 is hydrogen, alkyl, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl; or substituted heteroaryl; and, R 11 is hydrogen, substituted alkyl, heteroalkyl, substituted heteroalkyl, aryl, substituted aryl, heteroaryl; substituted heteroaryl or OR 12 ; and R 12 is hydrogen, substituted or unsubstituted alkyl, and substituted or unsubstituted heteroalkyl or substituted or unsubstituted aryl or heteroaryl.