In this work, we report the green synthesis of five emissive organoboron esters, obtained by a condensation reaction via one-pot three-component reaction under microwave irradiation in just 5 min, yielding quantitative yields. The molecular structure proposed in solution (1H, 11B and high-resolution mass spectrometry) was corroborated through X-ray diffraction analysis for 3c, where the boron ion resides in distorted tetrahedral geometry. The photophysical properties of organoboron esters were obtained in solution state, revealing that these molecular materials could be classified as semiconductors with a fluorescence quantum yield in the 0.70–32 % range. Furthermore, organoboron ester 3a demonstrated a non-hazardous selective fluorescent yellow stain against Staphylococcus aureus and Bacillus subtills strains. To the best of our knowledge, this is the first report of the use of a non-toxic organoboron ester compound as a selective fluorescent dye against Gram-positive bacterial.