We report a search for the standard model Higgs boson in the missing energy and acoplanar b-jet topology, using an integrated luminosity of 0.93 fb;{-1} recorded by the D0 detector at the Fermilab Tevatron pp[over ] Collider. The analysis includes signal contributions from pp[over ]-->ZH-->nunu[over ]bb[over ], as well as from WH production in which the charged lepton from the W boson decay is undetected. Neural networks are used to separate signal from background. In the absence of a signal, we set limits on sigma(pp[over ]-->VH)xB(H-->bb[over ]) at the 95% C.L. of 2.6-2.3 pb, for Higgs boson masses in the range 105-135 GeV, where V=W, Z. The corresponding expected limits range from 2.8 to 2.0 pb.