import { Component, OnInit } from '@angular/core';
import { AngularFire, FirebaseObjectObservable } from 'angularfire2';

@Component({
  selector: 'app-revista',
  templateUrl: './revista.component.html',
  styleUrls: ['./revista.component.css']
})
export class RevistaComponent {
  blog: FirebaseObjectObservable<any []>;

  constructor(private af: AngularFire) {
    this.blog = af.database.object('/blog');
    console.log(this.blog);
  }

  ngOnInit() {
  }

}

<div materialize class="nav"></div>
<div class="contain" id="topo">
  <div class="row">
    <div class="col s12 l9"><img src="assets/img/{{ blog.foto }}"></div>
    <div class="col s12 l3">
      <h4><a class="black-text" href="contato">Anuncie aqui!</a></h4>
    </div>
  </div>
  <div class="row">
    <div class="col s12 l9">
      <h3>{{ blog.titulo }}</h3>
      <h4>{{ blog.subtitulo }}</h4><br>
    {{ blog.texto }}</div>
    <div class="col s12 l3">Publicidade</div>
  </div>