Aspects of the disclosure are generally directed to probes and probe compositions for detecting or quantifying a target. One aspect provides a method for selectively hybridizing a probe to a polynucleotide by contacting a sample containing a first and second polynucleotide with a probe. The probe includes a number of nucleotides complementary to the first or second polynucleotide in the region of mismatch between the first and second polynucleotides. Another aspect provides arrays including the disclosed probes and methods of using the arrays and the probes.