Thereduced
free sulfhydrylgroupsallow fluorescentdyeswiththiol-reactive
groups (e.g., maleimideandiodoacetylderivatives)tobindsothat
numerous fluorophorescouldbefunctionalizedtotheinteriorof
the dBSA.Thedegreeof fluorescenceonBSAwereestimatedby
considering severalfactors(see S-2 in Supportinginformation).
Even thoughantibodiesthataredirectlylabeledwithamine-
reactive fluorophorescanbeusedforthedetectionofbacteriaas
a probe,thenumberof fluorophoresperantibodymoleculeis
nearlyintherangebetween3and9(Ogawaetal.,2009;Viraetal.,
2010), whichlimitsthelevelofdetection.