Zellnor Myrie and Jessica Ramos definitely have no Republican opponent
Rachel May - Janet Berl Burman (R). May also got the WP endorsement, so unless Valesky can run as an independent it will be a two person race
Robert Jackson - Melinda Crump (R). Jackson also got the WP endorsement and Crump got the Reform Party. No other candidate. Crump appears to run whenever the seat comes up. I am guessing that means the Republicans view this Senate seat as a lost cause
Biaggi is pretty much a shoo-in. Barring something unknown coming up, which I doubt, she should win. She is a former Cuomo staffer. There is a third candidate, Antonio Vitiello, think a less polished and more obnoxious Carl Paladino
Hope that helps a little.