The question comes up often about using the Cisco 40/100G BiDi QSFP28 optic for use with the Cisco Nexus 2348UPQ, or even other current Nexus 2300 FEX modules, instead of using the older 40G BiDi QSFP optic.
The quick answer is, no. The 40/100G BiDi optic is based on the QSFP28 standard and all the Cisco Nexus 2300 FEX QSFP up-link ports are based on the older QSFP standard. Since the 40G BiDi has a long lead time as of this writing, the best alternative option are Active Optical Cables (AOC).